thats normal this happens to people without problems. I was in class the other day and we had to write a paragraph about a memory of any kind. most picked going to lunch memories cause it was almost lunch time. then we had to answer some questions on a paper the professor handed out after we all got done writing. one fo the questions was- "while you were writing did you notice any sensory reactions?" There were answers like yea I could just smell that stew I was writing about, I could feel that burn I got when I spilled a pan of hot water on my leg, my stomach growled, my neck started aching from looking up when I was looking down at my paper but in what I wrote about I had been looking up watching airplanes flying in formation. Then the professor told us all that this is called body memories, and that every day of our life our brains have been doing just this storing memories and throwing them back in our faces when we think about something. Then he told us to go throw something in our faces its lunch time we would continue the topic next week.