A guy was in a bar playing pool with his pet monkey. The monkey jumps onto the table, grabs the cue ball and swallows it. The bartender freaks and starts yelling about how much cue balls cost. So the guy assures him the monkey will pass it and he'll wash the ball and bring it back.

Sure enough the guy and the monkey come back into the bar and gave the bartender his cue ball back. Meanwhile the monkey reaches into the peanut bowl, grabs a nut, sticks it in his butt--then eats it. The bartender stares at the monkey who continues to repeat this action again and again. So he asks the guy, "what's up with that?"

"What?"

"Your monkey keeps grabbing peanuts one at a time and sticking them in his butt then eating them."

"Oh, that---well, ever since the pool ball incident, he has to measure everything before he eats it."