A herd of buffalo can move only as fast
as the slowest buffalo. 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.
That's why you always feel smarter after a few beers.