Why there are different boxes of condoms(not a poem)

A father and son go in to the grocery store when they happen upon the condom isle. The son asks his father why are there so many different boxes of condoms. The father replies, "Well, you see that 3-pack? That's for when your in high school. You have 2 for Friday night and 1 for Saturday night."
The son then asks his father, "What's the 6-pack for?"
The father replies "Well that's for when your in college. You have 2 for Friday night 2 for Saturday night and 2 for Sunday morning."
Then the son asks "What's the 12-pack for?"
The father then replies "That's for when your married, You have 1 for January, 1 for February, 1 march................"