Do you remember me?
I ran into a guy I worked with a long time ago, and he called my name, but I didn't recognize him. He said "you don't remember me do you?" to which I replied, "no but don't feel bad." Likewise, I always carry a fake Astronaut application form in my wallet just for the gag....I know, I'm an idiot.
A laugh can be a very powerful thing. Why, sometimes in life, it's the only weapon we have.