You may have been conditioned to think you are entitled to nothing. (You may not even feel entitled to exist.) You might not feel entitled to basic respect and human dignity from others, and therefore may not protect you, your time, your things, etc. You don’t feel entitled to what is genuinely yours.
Over-entitled peopled feel entitled to other people’s things and time and resources, and believe it should be for them, that they deserve it. They will incept bad self-esteem, abuse another person, to get access to what they believe should be for them. They won’t accept someone’s “no” and don’t respect their boundaries.
Healthy self-esteem, reasonable entitlement, and boundaries all work together. We should feel entitled over ourselves and our things, our time, and our resources, and entitled to set boundaries related to those things. The entitlement comes from knowing what is yours.