I have been thinking about this for 40 years and still can't figure it out. This is my real experience. How can science explain it?

It was the summer of 1984. I was fifteen years old and lived in a small town in the south. My life was not very good. At that time, television was not popular. People's nightlife was to enjoy the cool in the yard, play poker, or listen to the neighbors' stories about supernatural powers. I never believed in those things until something happened that night that still puzzles me.

It was almost ten o'clock that night. I was doing homework in my room and my parents had gone to bed. Suddenly, I heard someone outside the window calling my name softly - "Xiao Qiang..." The voice was very light, but it was particularly clear at night.

I was stunned. The voice was not someone else, but my cousin. His name is Li Zhiqiang, and he and I have been playing together since childhood. But the strange thing is that he died in a car accident three days ago, and my father went to the hospital to claim the body.

I thought I heard it wrong at first, but the voice came again, and it was still a familiar voice. The curtains moved slightly, and I mustered up the courage to open it and see - there was nothing outside.

I didn't dare to disturb my parents, and I just hid in my bed and endured that night.

The next morning, I went downstairs with a haggard face. Unexpectedly, my mother said with a worried look: "Your brother came to me in a dream last night, saying that you are timid and asked me not to scare you. He said he was not here to scare people, but just to say goodbye."

I was speechless for a while, and goose bumps appeared on my back. Am I not hallucinating? Did my mother also "meet" him?

The story is not over yet.

A week later, my father took me and my mother to sweep Li Zhiqiang's tomb. That place is at the foot of the mountain, and it is our family's ancestral grave. When I walked to his tomb, I saw a piece of paper under the tombstone. It was a crumpled letter paper, the kind that only Li Zhiqiang and I used when we wrote diaries together.

On the note was a sentence written crookedly: "Xiao Qiang, don't be afraid, I really just came to see you."

I remember clearly that when he was a child, he liked to write "bie" as "咇", and the typo was also eye-catching on the paper.

My parents also saw it, and no one said anything. On the way home that day, our family of three was very silent. The note was later burned by my father, saying that "the dead are the greatest" and don't think too much.

But I have never forgotten it.

Over the years, I have also tried to explain this incident with science. Maybe I was too nervous that night and had auditory hallucinations? Maybe the note was a prank by someone else? But I can't convince myself of these statements.

What makes me feel most weird is that after that period of time, I began to dream about him frequently. Sometimes in the dream, he took me to the river where we often went when we were children, and sometimes he didn't say anything, just stood there and watched me smile.

These dreams are so real that I can hardly distinguish the boundary between wakefulness and sleep.

I have looked up various theories about "ghosts", "residual consciousness" and "parallel space" on the Internet, and even read a lot of neuroscience books. But every time I see an explanation close to the edge of my experience, I can't help but think that science is cold after all, and the memory of that night is so gentle and weird.

Forty years have passed, I have started a family and my children are about to go to college. But every time I am alone late at night, I still think of that note, the sentence "Don't be afraid" that makes me nervous to this day.

If you ask me, do I really believe that he is back? I will say - I don't know.

But I know that the voice outside the window that night calling me "brother" softly was not an illusion.

You say, can this be explained by science?

Thank you for reading this.

There are always some things in life that are unsolvable, but real.

If you have similar experiences, please tell me, and we will try to understand this wonderful world together.