I remember it as well and I was nowhere near to the incident; but it was my grandpa's birthday and usually we'd go over for lunch. Remember leaving school and getting to my grandpa's house, where the TV was on and family members were talking about "a plane that hit the WTC" in the US. The news were broadcasting it live here in Brazil and we were questioning... - how can a plane hit a building like that?.
A few minutes later, bang... another one, no one could leave the TV... the rest we all know what happened.
So every 9/11 I remember of my grandpa, that I no longer have, and I also remember the horror of what humans can do to each other.