This father needs to go to the drug store, and decides to take his 5-year old son with him. They are walking down the isle with many boxes of condoms hanging on hooks, and the boy stops his dad and asks,

"Dad, what are these?"

The father answers, "Well, son, when you are a teenager you will learn all about that."

They continue down the isle when suddenly the boy says,

"Say, dad -- there are THREE in this box, why is that?"

The father wisely answers, "Well, son, when you are in high school, you will learn that one is for Friday night, one for Saturday night, and one for Sunday night."

The boy seems satisfied with that answer, but as he continues down the isle he notices a box of SIX. "Dad, why six?" "

Well, son, when you are in college, you will appreciate that you will have two for Friday night, two for Saturday night, and two for Sunday night!" the dad answers.

Towards the end of the row, he spies TWELVE pack. "Hey, dad, why a box of twelve?"

"Well, son, when you are married you will learn that one is for January, one for February, one for March. . . . "