A Brainy Joke

brainA brain and a pair of jumper cables walk into a bar. The brain says, “Can I get a couple of beers from me and my friend here?”
The bartender says, “There’s no way I’m going to serve you.”
“Why not?” asked the brain.
The bartender explained, “Well, you’re clearly out of your head, and your friend looks like he’s about to start something.”