When we don't tell other people about our boundaries, we prevent them from really knowing us, creating a sort of "secret self." Sometimes we do this out of fear. We might worry that people won't like "the real me," or think we'll be rejected because our opinions are different.
One consequence of this behaviour is that we develop a set of rules for judging ourselves that is different from how we judge others. Unconsciously, we can begin to think that the opinions we hide from others must be "bad," and the more we are hiding, the worse we must be. As usual, it is all too easy to be our own worst critic and fail to apply to ourselves the compassion that we would naturally show toward a friend.
When we don't assert our boundaries with the important people in our lives, we are essentially hiding our real selves behind a mask. When we feel like an impostor, kindness toward ourselves does not come easily.
You know that sense of relief when you finally work up the courage to tell someone what you really think about something? Part of that relief is because you've given yourself permission to feel okay about your beliefs. By risking authenticity and asserting your boundaries, your hidden self is no longer buried and self-compassion has a place to take root.
Being honest about boundaries invites others to do the same. An awareness of what we have in common will then grow exponentially. What evolves from this is a true sense of empathy toward others, and the ability to respect differences in others because we are able to accept our own.