As told by Matt Damon to Jon Stewart on The Daily Show last night. I'm recounting this as best as I can from memory. Hopefully it comes across just as funny.

Matt: My father told me a story about a Grizzly Bear back in 1986...almost 25 years ago when he went up to Alaska. He was being shown around Alaska by a Guide and he noticed him carrying a .44 Magnum in a holster, but the sight on the gun was filed down. My father asked the Guide if the gun was for bears and the Guide said it was. My father asked him if he could ask a question about the gun? The Guide said "Sure". Why is the sight filed down? The Guide said "After I shoot the bear, it will hurt a lot less when the bear shoves the gun up my ass".