I had just turned 3 years old but I remember when JFK was shot and what I was doing, where I was. Same with 9/11.
After you and others posted about the Challenger, and you about the Iraq War I remember those as well. But those probably don’t count if I didn’t recall them on my own!
Just from my observation, the Challenger was everywhere - and I mean in years afterward. Obviously it was commonly seen as a flashbulb incident.
Whereas, the Iraq War start isn’t mentioned or shown much in years going by.
In fact, I doubt I would remember it much if not for that waitress coming over to tell us the news. If we hadn’t been out to eat - I bet I’d have no special memory.