Two hikers are walking up a mountain trail when a huge grizzly bear leaps out in front of them and roars. The first hiker gulps and sweats, frozen in fear; the other keeps his presence of mind and calmly advises, "Don't worry, just lie down and play dead and the bear will leave you alone."

"H-h-h-how do you know?" the first hiker asks.

"I read it in a book on wilderness survival."

"B-b-but what if the bear read the same book?"