I was in 5th grade, and it was a little after 5am when the news broke that the first Tower had been hit...
I didn't know what the WTC was, and I figured it was probably a piloting accident and it'd be on the news for a while...that it was really sad all those people died, but nothing else, really, except that it was probably going to be like when Princess Diana died.
Aside from LA-centered things like the OJ trial and the riots and especially the Northridge earthquake--I still remember waking up to see the fish tank we had at our old house smashed on the floor--Princess Diana's Death is really the oldest memory of a major tragedy that I can recall, so that was mostly what I had to compare 9/11 to at the time.
So I just thought it'd be like that.
My sister and I always watched cartoons downstairs for a bit before going up to change for school...
And JUST as I'm walking up the stairs and reach the top, I can see the TV in my mom's room...
And THAT was when the 2nd plane, on LIVE TV, started heading for the South Tower.
I watched it LIVE, and that changed EVERYTHING.
My sister and I then rushed to get dressed and go back downstairs to--completely against the normal inclination for a grade schooler--turn on the news...
And that was when he heard the PENTAGON had been hit, and I knew what that was, and that it was in Washington D.C., so this must be a nation-wide attack.
My mom was freaking out; my dad was supposed to fly back to North Carolina for a business meeting that weekend, and she called him immediately and repeated over and over that he had to cancel...
The radio was on in my 5th grade class, and so I heard a while later before class actually started, with the teachers and a few other kids that had arrived early, that the Towers had fallen.
That's one of the few classes that young where I can still remember something the teacher actually said almost verbatim...
The teacher said there was going to be a name we were going to probably hear A LOT over the next days, and probably longer, and asked if we had an idea who it was...
I asked if it was Saddam Hussein, as that was someone I knew from TV cartoons and the news and knew he was supposed to be an enemy...
He said "Probably him too, but..." and that was how I learned who Osama bin Laden was.
This sort of international politics and news-around-us session lasted about 20 minutes, then we had a break, and back to our regularly-scheduled class activities.
Went home, my dad canceled his flight plans (the planes were grounded for a few days afterward, so he couldn't have gone anyway) and I learned about the 4th plane that crashed in Pennsylvania because of its brave passengers, more news, and then bed.
And that was 9/11 for me, way back when.