lock the stable door after the horse has bolted

To try to prevent or rectify a problem after the damage has already been done. My father quit smoking after he was diagnosed with lung cancer, but I'm afraid he's locking the stable door after the horse has bolted.

See also: after, bolt, door, horse, lock, stable

Common Names:

Name	Pronounced	Usage
LÍDa	-	Czech
Victoria	vik-TAWR-ee-ə (English), vik-TO-ree-ah (German)	English, Spanish, Romanian, German, Swedish, Norwegian, Danish, Late Roman, Roman Mythology
Rawya	-	Arabic
Constans	-	Late Roman
ZoltÁN	ZOL-tahn	Hungarian
Petteri	PET-te-ree	Finnish