In Union Square Park:
Sometimes you only have a second to act when something happens, like, for example, Lady Gaga just happening to materialize right where you're standing. Then you get right on it, you raise your Pentax K1000 to your face, focus in, and depress the shutter. After she walks by, you realize that you never checked the aperture you were shooting at, and realize you had the thing way stopped down from the previous shot, so you get a grainy photoshopped mess that makes Bigfoot pictures look like they were taken by Richard Avedon.
But I'm sure if I stand in the same place long enough, Lady Gaga will come by again, and I'll be ready for her.