In one episode of 'Cheers', Cliff is seated at the bar describing the
Buffalo Theory to his buddy, Norm. (I don't think I've ever heard the
concept explained any better than this....)
"Well you see, Norm, it's like this... A herd of buffalo can only move as
fast as the slowest buffalo. And when the herd is 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.
Now, as we know, excessive intake of alcohol kills brain cells. But
naturally, it attacks the slowest and weakest brain cells first. In this
way, regular consumption of beer eliminates the weaker brain cells, making
the brain a faster and more efficient machine. And that, Norm, is why you
always feel smarter after a few beers."