"Ce qui est fait ne peut pas être défait"

Simplified Meaning:

Once something has happened, you can't go back and change it. Think of it like spilling a cup of milk. No matter how much you want to, you can't put the milk back in the cup; it's already on the floor. This idea is about accepting that what's in the past is permanent. If you made a mistake or a bad decision, you can't erase it. Instead of dwelling on it, it’s better to focus on what you can do now and in the future. For example, if you argued with a friend, you can't take back your words, but you can apologize and work on being a better friend in the future. This advice helps people move on from regrets and make the best out of their current situation.