The worst behaved students turn out to be the most pious preachers.
More German Proverbs:
Every clown can find fault, though it would puzzle him to do better.German
Envy envies itself.
German
Don't cry "Hurra!" till you are over the ditch.
German
Every man is dearest to himself.
German
No woman marries an old man for God's sake.
German
With one foot in the grave.
German