I was saddened and horrified watching the events unfold that day, but changed me??

No, that happened for me a LONG time before 9/11/01.
I guess spending almost 30 years on and around military bases puts me in a different view of "security". When terrorist events occurred around the world, we were always under heightened security measures. So the old saying of being situational aware has been a way of life for us.
But the event that opened my eyes to how vulnerable we could be... the bombing of the Marine barracks in 1983.

I lost a very good friend that day. Over the years, with every terrorism attempt around the world and who was usually claiming credit...well I always wondered how long before it came to our shores. They did attempt a few times, but it always seemed to be ignored or quickly forgotten.