Well first of all, it means that you should respect yourself. If someone is treating you poorly, say so. Yes, I went to the hospital, more than once, for exhaustion, but it was on projects I believed in and in some cases controlled. Never allow anyone to be a "slavedriver" to you externally or berate you in front of others. There are a lot of big egos in Hollywood, and most of them are just oversized balloons. They have no reason to be petty except that that they can. Nobody, as yet, has taken the time to pop them. Be the sharp object they need. Sure, Hollywood is all about who you know, but that means knowing, and being known by, the right people. People who want to work. To be professional. To treat other people like they ought to be treated. Trust me, there are more of them than any other kind.
Those are the ones worth carrying the water for.