It turns out, though, that those memories are full of errors. Ulric Neisser researches memories like these. In 1986 the space shuttle Challenger exploded upon take-off. Any of you reading this who are old enough to remember the Challenger explosion probably remember it vividly, i.e., as a flashbulb memory. Neisser took the opportunity to do some research. The day after the explosion he had his students (he is a professor) write down their memories of what had happened, where they were, what they were wearing, what the TV coverage was like, etc. Three years later he asked them to write down their memory of the event again. Most (over 90%) of the 3-yr later reports differed. Half of them were inaccurate in 2/3 of the details. One person, when shown her first description written three years earlier, on the day after the event, said, “I know that’s my handwriting, but I couldn’t possibly have written that”. Similar research has been conducted on the 9/11 memories, with similar results.

https://www.blog.theteamw.com/2010/08/27/100-things-you-should-know-about-people-41-you-are-sure-your-memories-are-accurate-but-theyre-not/