Saying no.
The social self is not comfortable in saying no. It will persuade us with rationalisations to say yes even when all our self wants to say no.
The most often used rationalisation is "what harm will this do?"
Saying no is a skill. And it's one skill that makes space for us to learn many other skills.
We get to do things we want to do only when we start saying no to things we don't want to do.