It's amazing how much 'mature wisdom' resembles being too tired.
A boy who gets a C- in 'Appreciation of Television' can't be all bad.
There ain't no such thing as a free lunch.
If a grasshopper tries to fight a lawnmower, one may admire his courage but not his judgement.
Wisdom includes not getting angry unnecessarily. The Law ignores trifles and the wise man does, too.
The greatest productive force is human selfishness.