Once had a guy who sat next to me in Chem and he said your mom jokes literally at least 20 times in about a half hour! "Your mom's chemistry, your mom's a mol, your mom's a proton, your mom's an electron."
I knew someone like this in high school. He had it really badly, to the point of *joining* conversations, delivering said line, and leaving. Constantly.
At one point, he did this just as myself and another lens-wearer were engaging in the near-inevitable struggle for dominance. (If you wear glasses, or have at some point, you know that whoever has the worst vision wins a subtle sort of cachet. It's best if you can establish this by *actually* exchanging frames, but quoting diopters will do for the contact set.) This led to the following:
Me: ... yeah, I'm pretty much blind without my glasses. Not literally, but...
Guy: Your MOM'S blind.
Me: ::Look of shock, anger, and repressed tears. Really good fake repressed tears:: Actually... she IS. ::glares::
Followed by about 15 seconds of horrified, pale-faced silence.
Guy:: (stammering) Dude... like, really? Man... I...
Me: (Conversationally) No, not really. I just wanted to mess with you.
It was a fine moment.
"... for a man to understand what he himself says is one thing, and to understand himself in what is said is something else." -Soren K.
An ironic motto of sorts:
The ability to quote is a serviceable substitute for wit. -W. Somerset Maugham.