I always wondered why it was so easy to remember a song or funny joke rather than some information I for a class. I have several different theories about this.
At least for me, I always seemed to remember things when I needed to know them. I always remember I thought was important. I have almost perfect memory when it comes to do with my hobbies or in a serious moment. I would be able to remember how to take apart an engine after doing it one time but remembering algebraic equations or the ATP cycle would take an eternity for me to learn because I don’t see those pieces of information as important or I don’t seeing myself using those pieces of information in everyday life.
Another theory I have about memory is when your trying to remember something which involves all 5 senses, taste, touch, hearing, sight, and smell. It maybe because of my adhd but I’m unsure.
I think everyone can remember where they were when they heard about 911 because I think most of their peers asked them the same question for a month after it occurred so it was well ingrained into their heads.
I think we can study powerful memories by asking people about 911 while in an FMRI machine. Then we could ask them what they had for breakfast last week. We could view what parts of the brain are activated during a powerful memory and short term memory.