I once dreamed about a swimming pool located in a city not far from my city. I had been there, but when I was only 3 or 5 years old, and I really don't remember what it was like inside. However, 3 years ago I dreamed about that place. But at that time, I didn't know where it was. Then, last year, I visited that swimming pool as a birthday gift. I saw that the swimming pool looked very similar to that one dream, and what I did at that time was also similar to my dream. I realized it and im so surprised. Is there a scientific theory behind why something like this can happen? I'm curious.