This goes a long way towards explaining a lot of things: 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. Excessive intake of alcohol, we all know, 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 thats why you always feel smarter after a few beers.