Many years ago, I went to Lilith Fair on the spur-of-the-moment (a friend of a friend had an extra ticket.) As usual, I had not prepared for the weather and it started raining. I wore friend-of-a-friend's extra flannel shirt (hey, it was the grunge era!) It was super ginormously huge on me - and for some reason, I stood on one leg (think tree pose in yoga) and kept saying, "I am Batman." while holding out my flannel "wings." (Frighteningly, I was stone cold sober - there's a reason I don't drink much - I'm weird enough without it, thanks.)
I ended up chatting with the peeps on the next blanket over, and I emailed one of the girls the next week. The email said "Hi, it's me - you know, Batman."
I still think that's the funniest email I've ever sent.
P.S. - Go see "Batman Begins" - it's decent! [High praise, coming from me.]