It's weird. I lived in LA at the time and I was in my early 20s. I remember my gf waking me up at 6:30am to go look at the TV. It doesn't feel like an historical or far-away event to me. It seems like the most pivotal moment of my life, when this country changed and everything changed. We were worried about LA being attacked, worried about bio/chem attacks. Suddenly there were no-fly lists, and things called TSA and Homeland Security. Domestic mass surveillance really started then ... it's when all the methods from the drug wars were brought onto American soil. Suddenly there were truther conspiracy theories on a fairly new site called YouTube. Suddenly psychopaths on local Texas radio made their way into the national conversation. And a year or so later I found myself kettled by cops at a protest against our invasion of Iraq. I posted a novel on my website that got a lot of hits from military IP addresses in Virginia and Iraq. A neighbor told me the police were going through my trash while I was at work. My apartment got broken into and only a laptop and my papers stolen. I left the US and lived abroad for 10 years.
When I think of Americans who were alive then and younger, or who weren't born, looking at it as a historical event, it boggles my mind. Everything about this country has been deformed and twisted, every aspect of the society you live in from security theater at the airport to the militarization of local police, all that hardware, to the way the giant internet sites function now (or don't), to all the conspiracy-fueled madness that led to 1/6/21, which is the only other day that began to feel like 9/11. All of it started that day, it's the moment when we entered the wrong alternate universe.