The robb’d that smiles, steals something from the thief.
He robs himself that spends a bootless grief.

– William Shakespeare

Othello, Act 1, Scene 3. The Duke of Venice uses the extended metaphor of stealing as he offers advice to an angry Brabantio, who feels robbed of a daughter by Othello. When you are a robbery victim it is better to smile and deny the thief the satisfaction of seeing you grieve, the Duke tells him. Otherwise you are only robbing yourself of further joy.