I've got this genetically coded ability to produce the enzyme that allows my body to break down milk. Not everyone has it. Its more of a european thing, the ability to take advantage of a certain food source, higher levels of fitness within a certain environment.
I have a friend who lacks the enzyme to break down gluten. So no wheat, no oats, no barley. He can't eat toast or drink beer.

But me, I should do nothing but smoke pot, drink milk and eat toast, because I can.

God I'd be the size of a fucking house.