Warnings and Errors!
A guy is standing on the corner of the street smoking one cigarette after another.
A lady walking by notices him and says, "Hey, don't you know that those things can kill you? I mean, didn't you see the giant warning on the box?!"
"That's OK," says the guy, puffing casually, "I'm a computer programmer."
"So? What's that got to do with anything?"
"We don't care about warnings. We only care about errors."