A man stomps into a bar. He is obviously angry. He growls at the bartender, "Give me a beer!" He takes a slug of the beer, and then he shouts out, "All lawyers are idiots!!"
A guy at the other end of the bar yells back at him, "You take that back!"
The angry man growls, "Why? Are you a lawyer?"
The guy replies, "No, I'm an idiot!"
I don't understand this joke!