If we lack self-esteem, we may not feel able to influence others. However, starting with small situations, it is possible to build our confidence.
To be authentic, we may need to expose ourselves to rejection and unwelcome attention.
If we need to be right all the time, then we may get our own way. But, in the process, we may miss the chance to help others and make friends.
Assertiveness is a moderate way of influencing people and events, more engaged than avoidance, and less invasive than aggression.
There are great relational advantages in signalling to others our values, intentions and identity. Not least, it helps us to enlist support and make space for ourselves.
Boundaries can be useful. But they can also be badly misused, even by therapists.