Stress
The world of the high-powered agent is cutthroat and aggressive and the workload is almost never-ending.
Several things could go wrong: one of your clients misses his call time and now a studio is losing twenty grand a second that he doesn't show; your most successful singer just left you a message saying that she's jumping to a rival agency; the junior agent you just hired accidentally deleted your entire royalty check database so you have no idea who is supposed to be paid what for which.
And all of that just happened in the last seven seconds.
The agent world is not for the faint of heart, or the faint of back, knees, or stomach. Fortunately, if this isn't the right job for you, you'll figure it out quicker than some entitled jerk can shout his overly-complicated latte demands at you.