A guy lives on the top of a mountain and the only store is 10 miles down the mountain. One day the guy walks all the way down to the store and asks the clerk for some dog food. The clerk replied "Sorry, but I have to see the dog first." So, the guy walked all the way back up the mountain, got his dog, went back down, and got his food.

The following day, he comes down again and asks for some cat food. The clerk replies. "Sorry, but I need to see the cat first." So, he walks all the way up the mountain, all the way down, and back up again.

Again on the following day the man comes down, but this time carrying a paper bag. He gets to the store and the clerk asks, "What in the bag." He takes it, looks and yells "OH SHIT!"

"Yep, that's right, I need three rolls of toilet paper."