This was a perfect moment, and I blew it. The girl was staring off with these beautiful, shining blue eyes, but you'd never know because the camera was set to -1 exposure compensation, and I exposed for the sky. The sky is 1 stop under, and she is probably 3 or 4 stops underexposed.
There are many ways to miss the shot. Usually I miss it because I wait too long, and the moment dissolves before my eyes. Someone stands in front of my subject, or the subject walks away or loses the facial expression. I've been trying to train myself not to hesitate, but then there's always the risk of screwing up the exposure or focus anyway.
It's discouraging to miss such pregnant moments, but it's not the end of the world. There will be other shining blue eyes on the T. Street photography isn't hard; it just takes an awful lot of time.