There is a lot of avoidance ; we don't dare and we wait, especially if we fear being overwhelmed by an emotion. And the longer we wait, the more it will become necessary to build a kind of dike to stop this emotion. And the more it will strengthen.
So the sooner we can do it, the better.
The brakes can be a problem of education, a stake of work, the pressure to satisfy the other...; all this conditions the fact of taking even more on oneself and alters, in a generally slow process, self-esteem.
Knowing how to say yes is certainly useful; Atlas, when he takes the world on his shoulders, is very concerned about issues that concern everyone. But this resource of attention to others can be counter-productive; therefore, without becoming selfish, it is beneficial to slowly learn to disengage.