The problem with common sense is that it a’int so common.

Ralph Waldo Emerson, Art (1841)
On dit quelquefois: “Le sens commun est fort rare.”

Common sense always speaks too late. Common sense is the guy who tells you you ought to have had your brakes relined last week before you smashed a front end this week. Common sense is the Monday morning quarterback who could have won the ball game if he had been on the team. But he never is. He’s high up in the stands with a flask on his hip. Common sense is the little man in a grey suit who never makes a mistake in addition. But it’s always somebody else’s money he’s adding up.