Egon: You get a given pocket pair 1/221 hands. I think you might be getting confused by the 169 different types of hands in a range selector like PokerStove. That's not taking into account the different combinations of each type. KK is 6 combinations out of a possible 1,326.
OP: The # of times you run KK into AA depends on how many opponents you have.
HU - 1 out of 204 KKs
6Max (5 opponents) - 1 out of 41 KKs
FR (8 opponents) - 1 out of 26 KKs
So, in FR, you'll run KK into AA about once every 5,500 hands. In 6max, about every 8900 hands.
More importantly, normally no money is made in these spots in the long term in poker. They simply don't matter. Since we virtually all play them the same, there's no difference in our strategy and therefore no edge to either player.