We care about other people's feelings more than our own, and then we have trouble setting good boundaries with people. So in this way, we see a lot of social situations where one person becomes the mediator, or even the therapist,. And so that they learn to do, what they evolve to do, is set their feelings aside for the sake of harmony. It's not that you can't stand up for yourself. It's that your brain has adapted to prioritize harmony over personal satisfaction.