One night at Cheers, Cliff Clavin said to his buddy, Norm Peterson: 
  "Well, 
         ya 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. 
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 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.