A paranoid man is a man who knows a little about what's going on. William S. Burroughs
Hunger knows no friend but its feeder. Aristophanes
He will win who knows when to fight and when not to fight. Sun Tzu
The echo knows all languages. Finnish Proverb
The fox knows a lot, but a woman in love knows even more. Spanish Proverb
He who knows much, does not speak much. Ethiopian Proverb