I was in 7th grade at the time. For me, I honestly wasn't really all that moved either way by it. My mind was elsewhere, and I, being the young, uninformed little poser anarchist was like "Yeah, *bleep* the government rabble rabble".
The only thing I give 12 year old me credit for is calling b/s on all the bandwagon patriots that sprung up immediately after. It bothered me that on my street there were three American flags prior to 9/11, and right after, there were maybe three houses that weren't flying it. I mean, yeah, it's a great nation, but you didn't show your support prior to the attacks.
The "patriotism" really did have good intentions, but it just bugged me a lot that it took THAT to get people to express some pride in their country, and it still does.