I was a junior in college and saw it on TV at a cafe at school. I immediately called my reserve center. I was in the LCpl in the Marine Corps reserves. I ended up spending 2 of the next 4 years on active duty spread over 3 separate activations/deployments. It definitely changed the trajectory of my life. I met tons of people I wouldn't have met otherwise. It took me 7 years vs 4 to finish college. I'm probably in the same job field I would have been in otherwise. Who knows if I would have met my wife. We have a 1yo baby now. Who knows what would have happened. That attack set into motion a global chain of events that has effected millions of people and killed tens of thousands.