I've been examining my reaction (is that navel-gazing? LOL) and realized it's because it rekindled 9/11 for me. I cried spontaneously for two months after that (and have also developed mild Tourette's in that I became rather potty-mouthed, seriously).
It's interesting, how we have emotional memory that can be so quickly recalled... I was robbed at gun-point once, and when the incident was over I collapsed out of shock. A month later, friends pulled up into my driveway on motorcycles at night (my attackers had arrived in similar manner, but in daylight). I may by then have been the possessor of a Mossberg Intimidator with laser sighting, I may have grabbed and pointed it... but the weak-legged adrenalin bomb kicked in exactly the same regardless.
Wait a minute... getting mugged made me a gun lover, how come America ain't reacting in the same manner? Impeach Mineta!