Well, quoting is a natural thing in many cultures. We do it because a phrase makes us think about one topic, makes us consider things from an angle we didn't put our minds at or... because they're just too funny to let them pass without an afterthought.
I think it'd be nice to make a compilation of quotes we know or hear somewhere. Here's one I consider spot on and funny for starting up:
"Tattoos are an important marker of maturity in some cultures, and of immaturity in others."
Found in a beer related site for the Dos Equis brand.
What was I doing reading a beer site? Would you believe me I don't know how I ended there?