I’ve always enjoyed working out, but once I discovered snowboarding, my perception of the pleasure that sports can bring completely changed. I fell in love with snowboarding and trained throughout the year to be physically ready for it. I eagerly awaited winter to head to the ski slopes and spend time in the surrounding villages, escaping the temperature inversion, pollution, and noise of the city.

The silence and beauty of the snow-covered mountains and the sensation of floating on fresh, untouched powder snow took me to the peak of pleasure I could ever imagine. The crisp, cold mountain air energized me, and a sense of vitality and being alive ignited within me.

Several years ago, when I went snowboarding with my Polish friends, I severely injured my back during a jump. This injury caused severe pain in my lower back and right leg, and soon, it led to tingling in my feet and difficulty walking. After seeing a physiotherapist and getting a full MRI of my back and neck, I discovered that I had a herniated disc that needed immediate treatment. The snowboarding injury, combined with congenital spinal stenosis, made the situation even worse. On the physiotherapist’s advice, I started therapy sessions. After a month of physiotherapy, not only did the pain not improve, but the tingling in my foot and difficulty walking worsened to the point that I had to stop going to the gym and faced challenges with daily activities. After that, I visited several other specialists, all of whom recommended surgery, which did not seem particularly promising. I even remember one specialist telling me there was a chance I could end up paralyzed from the waist down after the surgery, so I should be prepared for that.

One of my friends introduced me to a neurosurgeon, but getting an appointment with him was very difficult. The first available appointment was months away, so I had to live with the pain for several more months. My previously active life—starting with early morning runs, followed by hours of programming and attending numerous company meetings, and concluding with snowboarding sessions over the weekend—had turned into a painful, sedentary existence with an uncertain future.

The only thing all the doctors agreed on was walking in the pool, so I spent half of my day at the pool, with headphones on, listening to audiobooks that became my saviors during this difficult time.

When I finally met the neurosurgeon, hope was reignited. He told me not to work for four months, avoid using a laptop and computer entirely, not exercise, and limit walking to the pool only. I should lie on my side in bed with a pillow between my legs for the rest of the day and return for a follow-up after that period. He also asked if I had ever had an MRI in the past, to which I said yes. About 10 years ago, I had an MRI due to recurrent back pain caused by long hours of sitting in front of the computer. The doctor asked me to bring that MRI as well. He prescribed medication to reduce pain and inflammation, but they didn’t help much.

Those four months became one of the most painful yet productive periods of my life after compulsory military service. The first few weeks were spent watching movies and series and listening to audiobooks while walking in the pool, but this became tedious since I was used to a more active and productive lifestyle. After a while, watching movies and series gave way to writing my first book. As it coincided with my return from a trip to Finland and Norway in search of the Northern Lights, I began writing a cultural travelogue, which later got published under the title The Arctic Circle. My writing career started right there. Right after finishing that book, I began my second one, Playing with Death, and all the idle moments I spent in bed turned into golden opportunities for learning through audiobooks, with the fruits of that learning being the books that brought hope back into my life.

I wrote both books using my phone, while lying in bed, and partly while walking in the pool.

A few months later, I returned to my doctor with both the old and new MRIs. He performed the usual neurological response tests and reviewed both MRIs. He asked, “How are you feeling? Is your pain still there, or has it improved?” I replied, disappointed, that there had been no improvement. The doctor shook his head and said, “You don’t have any problem. Go back to living your life.” My eyes widened with surprise, and I said, “What do you mean, doctor? I barely managed to make it to your office, and I’ve been doing everything you told me for months!” The doctor said, “That hernia that other doctors mentioned, you’ve always had it. I compared it with your MRI from 10 years ago, and nothing has changed. Besides, all your motor tests are perfect. Your physical condition is better than mine.” Before he could finish, he asked, “Have you ever heard of Phantom Limb Syndrome?” I replied, “No, I’m a programmer, so I don’t know much about medical stuff.” The doctor smiled and said, “No problem. In short, your brain is creating pain that doesn’t actually exist. I can give you a medication to essentially reset this process.” At the time, I had no knowledge of the brain or nervous system and just stared at the doctor in shock, barely able to speak. “So, it’s possible that my brain has been creating all this pain?” I hadn’t even left the office when I started researching similar cases—people who experienced severe physical pain despite the absence of any real injury, including the story of someone who passed out from intense pain caused by a nail that had pierced between their toes.

In 1995, a famous story was published in the British Medical Journal, illustrating an example of experiencing pain without physical injury. The story was about a 29-year-old construction worker who, while jumping off a plank, accidentally stepped on a 15cm nail. He felt excruciating pain and was immediately rushed to the emergency room. Every small movement caused him unbearable pain, so much so that doctors had to sedate him with fentanyl and midazolam just to pull the nail out of his shoe.

However, when they removed his shoe, it was revealed that the nail had merely passed between his toes without causing any actual injury. Yet, he had experienced intense pain due to the fear and belief that he had been injured.

This story is often used in pain psychology research as an example of “pain without injury” or nociception.

This sparked my interest in how the brain and nervous system work, leading to my studies in neuroscience.

The term I will frequently use in this section is the “Expectation Effect.” Understanding what I call the Expectation Effect requires reading this entire book, but in short, it refers to the influence that expectations have on the mind’s perception. This effect can simultaneously impact the content of awareness and the mental background, thus influencing what the mind perceives.

A few days ago, while driving, I slowed down as I approached a pedestrian crossing to stop for a pedestrian waiting at the side of the road. At that moment, the pedestrian pressed the crossing button. My attention was drawn to the green traffic light, and I realized that the light was green for cars, meaning the pedestrian had to wait for it to turn red before crossing. So, I didn’t stop the car and continued driving. Just a few meters before the crosswalk, my passenger yelled that the light was red, and I slammed on the brakes to stop the car! The pedestrian had mistakenly pressed the button while the light for them was green and mine was red. This created an Expectation Effect in my brain, and I saw the red light as green because my mind had linked the act of pressing the button with the light being green for cars, leading to this mistaken perception. It was obvious that after this mistake, a feeling of shame and regret accompanied the realization of this error, and that unpleasant feeling stayed with me for hours afterward.

Before I move away from this crosswalk example, I want to share another related observation that caught my attention from living between Turkey and Portugal. In many countries, including Turkey, stopping for pedestrians at crosswalks is not common, while in other countries, particularly European ones like Portugal, it is a sensitive matter. The feeling pedestrians experience in these two types of countries is very different. If you live in a country where stopping for pedestrians is uncommon and suddenly someone does stop for you, it may create a pleasant feeling, and you will sincerely appreciate the polite driver. Conversely, you won’t feel too bad when other drivers don’t stop. But if you move to a country where this is taken very seriously, after a while, the situation reverses—you no longer feel anything special when drivers stop, but when they don’t, it sparks anger and a sense of disrespect in you. Our expectations can significantly affect the emotions we experience. Initially, this confused me. When I returned to Turkey from Portugal and drivers didn’t stop, I felt bad and constantly had to remind myself that it wasn’t part of the local culture and that people in Portugal drive much worse, so why should I expect more here? But my dear brain didn’t care for such reasoning—my experience living in Portugal had changed my expectations, and my emotions were following suit.

The Expectation Effect is not limited to sensory errors or emotional experiences; it can have much deeper effects on what we experience in life. If you search for the term Placebo Effect on Google Scholar, a search engine for scientific papers, you’ll find thousands of studies and articles, each in some way proving the influence of suggestion in life. The Placebo Effect is a type of Expectation Effect that can change our perception of reality.

When you’re prescribed a medication (whether medical or a specific food supplement), a large part of the effect comes from suggestion in addition to the biological effect. This can sometimes be so powerful that a placebo (a sugar pill) can produce the same effect as the actual drug in some individuals, underscoring the importance of the Expectation Effect.

In addition to the Placebo Effect, we should also consider the Nocebo Effect, which refers to the harmful impact of suggestion. In other words, believing something to be harmful can have damaging consequences. One of the most common examples of the Nocebo Effect in daily life is searching for the symptoms and side effects of diseases and medications on search engines. Many people, including myself, experience symptoms of a disease or side effects of a drug or substance after reading about them.

Similarly, take a look at the Belief Effect. If you search this keyword, you’ll find even more results, and the number of papers and books on this topic is astounding. I categorize the Belief Effect as another type of Expectation Effect.

Our beliefs and convictions can significantly shape what we call reality. Simply put, if you have a modern, scientific outlook, what medicine and science offer will have a stronger impact on you. If you hold a religious-traditional worldview, prayer and your religion’s practices will be more effective. One of the most fascinating researchers in this field is Alia Crum, whose work you can explore in the scientific resources at the end of this book if you are interested.

Most of us know how the moon changes daily, transforming from a crescent to a full moon. In simple terms, we all know that when the moon is not actually full or crescent, it’s the sunlight being blocked by the earth that gives it this appearance. Yet, we still say the moon is crescent or full. The moon never becomes full or crescent; it stays right where it is, and only the reflection of its light changes. But as we enjoy watching the rise of the full moon or the beautiful crescent moon, we often don’t think about the dark side of the moon, assuming the moon has actually taken on that shape. Many people still believe that when the moon is full, they experience a different feeling, without realizing that it’s just a reflection of light and nothing more. What they’re experiencing is nothing but the Expectation or Belief Effect.

Recently, I had this conversation with a friend who was deeply affected by the full moon, and I explained the subject in detail. As usual, the intense emotions of having their beliefs challenged took over, and not only did they refuse to listen to my explanation, but it also created a strain in our friendship. You may also have similar feelings after reading this, which is completely natural. My friend explained to me that the full moon is highly influential, and you can clearly see how it affects the sea, causing tides. I asked them, “Do you think the full moon causes the sea to ebb or flow?” They paused for a moment, then reached for their phone to look up the answer. I asked them to refrain and let the discussion continue naturally. I explained that tides have nothing to do with the fullness of the moon and occur every 24 hours, during the earth’s rotation. There have been many studies on the full moon proving that the moon’s fullness—or rather, the illusion of a full moon—has no effect on people’s emotions unless they are told it’s a full moon.

In these studies, people who believed in the full moon’s effect on their emotions were divided into groups. One group was told the moon was full, and a full moon was shown to them on a screen, although in reality, the moon was not full. Another group was shown a half-moon while the moon was actually full. And finally, a group was shown the real full moon. None of these individuals were aware of the actual state of the moon. Those who were told the moon was full, regardless of whether it was full or not, experienced the effects of the full moon. Meanwhile, those shown a half-moon, even though the moon was full, did not feel any effects. Additionally, those who did not believe in the full moon’s effect experienced no changes in any of these conditions.

These studies show that the only minor impact the full moon has on individuals is due to its increased brightness, which affects those sensitive to light. However, even this effect disappears by simply closing your curtains. Moreover, the light’s effect is far less significant than that of phone screens, TVs, or indoor lighting. This phenomenon is sometimes referred to as “cultural placebo.”

Various research sources on the cultural placebo effect of the full moon can be found in the resource section at the end of the book.

If our expectations can influence what we experience in any given moment, it becomes clear that the reality each of us is experiencing is different and constantly evolving.