Waste not your Hour, nor in the vain pursuit Of This and That endeavour and dispute; Better be jocund with the fruitful Grape Than sadden after none, or bitter, Fruit.
Omar Khayyam http://classics.mit.edu/Khayyam/rubaiyat.html Verse LIV
Translation: it's better to be drunk.
Not sure this qualifies as a rationality quote.
Another month, another rationality quotes thread. The rules are: