I've seen this a few times thoughout my net exploration, and decided that it was time to share it with others.
A herd of buffalo can only move as fast as the slowest buffalo. And when the herd is being hunted, it is the slowest and weakest ones at the back that are killed first. This natural selection is good for the herd as a whole, because the general speed and health of the whole group keeps improving by the regular killing of the weakest members.
In much the same way, the human brain can only operate as fast as the slowest brain cells. Excessive intake of alcohol, as we know, kills brain cells. But naturally, it attacks the slowest and weakest brain cells first.
In this way, regular consumption of alcohol eliminates the weaker brain cells, making the brain a faster and more efficient machine. That's why you always feel smarter after a few shots and a couple of beers.