Power
We wish we could tell you that you're one of the big movers and shakers in the industry. That your status is only slightly below that of your employer, and that the two of you are friends as much as you are business associates. We'd like to tell you that, but we don't want to give you an overdeveloped sense of hope in a hopeless world.
If Hollywood is a totem pole of power, you're the foundation that is buried half underground beneath the lowest man on the pole. Despite how much money you're making and how well your lifestyle may be because of it, at the end of the day you're a glorified lackey ready to answer your boss's beck and call at a moment's notice. When your celeb says jump, you ask, "How high?"
So how do you deal with this lack of personal power? Take it out on those who have even less power than you, of course (but not really, of course). You'll be dealing with a large amount of vendors, receptionists, secretaries, customer service agents, concierges, and others who live to serve.
Generally, you need to be good to those around you, but when you're on the clock and they're running behind or didn't get the order right or are missing your package, you might feel a little more entitled to let loose an aggravated sigh.
After all, your celebrity may let loose a whole lot more than that if everything isn't perfect.