trying to stop something bad happening when it has already happened and the situation cannot be changed.

Improving security after a major theft would seem to be a bit like closing the stable door after the horse has bolted.

• Don't count your chickens.
• Don't count your chickens before they're hatched.
• Don't get mad, get even.
• Don't get me wrong.
• don't get me wrong
• Don't give me that!
• Don't give up the day job!
• Don't hold your breath.
• Don't make me laugh.
• don't mention it
• don't need this
• don't rock the boat
• Don't spare the horses.
• Don't sweat it!
• Don't sweat the small stuff.
• Don't take any wooden nickels.
• don't you dare
• do nut
• doom and gloom
• do one better
• do one better than
• do one better than someone
• do one better than something
• do-or-die
• door to door