Knowing where your own boundaries are is essential to a well-lived life. If you don't have them, you are essentially powerless to consciously fulfill your own desires and expectations. You will be prone to expecting others to fulfill the for you, and that won't happen. You set yourself up for failure when you don't know who you are.
because you will end up becoming some else's servant
Because if you should ever run into a person that wants to challenge them, for example a Narcissist, you'll be able to maintain them....it's really an important thing to do. I didn't know how and I got hurt.