I'm a New Yorker, I was here on 9/11. My neighbor died (left a wife and three children under 6) and I know two people who ended up with PTSD after leaving the towers.
What triggers a memory for me is seeing a crystal clear blue sky as it was on that day and hearing jets that sound like fighter jets, which we had here for a while.

Here's the reality of the situation: the vast majority of people who lost someone have moved on with their lives. The wife of my neighbor who died has remarried and the children are a decade older, they have a father. People who were really here are all much stronger for it. A friend with PTSD has medication and gets therapy. He's told me he really doesn't think about it either.

And should fearful or negative thinking surface I change the channel (my brain) by deciding I want to watch another show.