There's a man trying to cross the street. As he steps off the curb a car comes screaming around the corner and heads straight for him. The man walks faster, trying to hurry across the street, but the car changes lanes and is still coming at him.
So the guy turns around to go back, but the car changes lanes again and is still coming at him.
By now, the car is so close and the man so scared that he just freezes and stops in the middle of the road.
The car gets real close, then swerves at the last possible moment and screeches to a halt right next him.
The driver rolls down the window.
The driver is a squirrel.
The squirrel says to the man says, "See, it's not as easy as it looks, is it?"
You don't stop laughing because you grow old, you grow old because you stopped laughing.