It means to dwell on past mistakes or misfortunes that cannot be undone. It's a reminder to accept what has happened and move on, rather than wasting time and energy on something that is already done.
spilt milk
This means something that's done and can't be undone. Least said, soonest forgotten. Don't cry over spilt milk. Sometimes it's best to forget past hurts or mistakes and just move on.
Don't cry over spilt milk.
"It's no use crying over spilt milk!" is an idiom that means that something that you have no control over has happened, so it is no use feeling sorry for yourself.
When you cry over spilt milk
She was full of an emotion.
Fraggle Rock - 1983 Don't Cry Over Spilt Milk 1-10 is rated/received certificates of: Australia:G
I had a big incident in acafeteria because I spilt my milk all over the floor.
It means to pass away, as in a storm that blows over and is gone.
This expression means that there is no use in getting upset over something that has already happened and cannot be changed. It advises letting go of past mistakes or mishaps and moving forward positively.
Some examples of idioms in "To Kill a Mockingbird" by Harper Lee include "bought the farm" meaning to die, "cry over spilt milk" meaning to regret something that has already happened, and "barking up the wrong tree" meaning to pursue the wrong course of action.
The literal meaning is to be in water that is deeper than one is tall. The idiomatic meaning is to be too deeply involved with someone or something, beyond what one can deal with.