A man walks into a bar and sees a horse sitting at the counter, sipping on a beer.
Intrigued, the man asks the bartender, "What's up with the horse?"
The bartender replies, "Oh, that's Charlie. He's a regular here. In fact, he's the smartest horse you'll ever meet. Watch this."
The bartender walks up to the horse and whispers something in its ear. The horse then nods, takes a sip of his beer, and starts doing complex mathematical equations on a napkin.
The man is astounded and asks the bartender, "Can I try that?"
The bartender nods and tells the man to whisper something in Charlie's ear. The man leans in and whispers, "Hey Charlie, how about you go outside and graze on some grass?"
Charlie looks at the man, shakes his head, and continues working on his equations.
The man is confused and asks the bartender what happened. The bartender chuckles and says, "Well, you see, Charlie here is a genius, but he's also a bit of a smartass. He only listens to complex commands. Just tell him to solve the equation for the square root of negative one and he'll do whatever you want."