Picking your battles is half the battle.

The whole 'no until absolutely yes' thing is on point. If like many people you have a tendency to want to please everyone, and so you say yes to basically everything, before long you will find yourself in a trap, too busy to do what you really want to do. At the same time, we should never regret the experiences we have had, as they are what lead you to where you are, but it doesn't mean they should dictate your next moves. Saying yes all the time means that you have less agency over your next moves. That's why we need to practice letting people down softly, leaving behind only the things that we really want to do.