Stress
Because your clients are relying on your expertise to such a huge degree, there's a lot of pressure on you to come through with a win. They're not paying you big bank just to have you advise them they should install a pool table in the women's restroom. That's silly. Obviously, it should be in the men's room.
And over time, as you grow in rank (and, most likely, girth), you'll be expected to win deals à la Greg McGeekerson. Lose deals and you're likely out, meaning that the firm that manages you strong encourages you to go find a client for whom to work.