Candy Bars

Little Johnny was sitting on a park bench munching on one candy bar after another.
After the sixth one a man on the bench across from him said :
- Son, you know eating all that candy isn't good for you. It will give you acne, rot your teeth, make you fat.
Little Johnny replied :
- My grandfather lived to be 105 years old.
The man asked :
- Did your grandfather eat 6 candy bars at a time ?
Little Johnny answered :
- No, he minded his own business !