Milk is a drink that must be handled carefully. What does it mean? You cannot boil it, you cannot pour it too fast, and in case you spill it... don't cry. There's no point crying over spilt milk. Just KEEP CALM :)Cry over spilt milk means to be upset over something that cannot be fixed.
Definition: when you complain about a loss from the past.
Example: there's no point crying over spilt milk.