I know in this business we talk a lot about being thick-skinned and tough, but it's not only this type of "tough" that is a challenge. You really have to be physically tough and have strong will power to succeed in this business. Some nights you really put your body through a torture test. Pulling an all-nighter, or finishing up at 3AM and coming in for the 8AM (I call it "the pinch" where the CD responds late at night and the account team plans the meeting early). And even the thick-skinned part of it is more about being calm after the client doesn't like what you spent all that time doing. When you just think "man, I could've been sleeping". It's keeping Zen while getting beaten, and smiling, and thanking, and asking for one more shot.
A long time ago I read a book (whose name I can't recall) about a kid growing up in Spanish Harlem. At one point he's talking about street fighting, and getting punched. How you can't flinch, because if you do, that next punch is about to land. He said the way you show you're a tough fighter is that you don't flinch, you sniff up the blood and look them dead in the eye.
So next time a client, or CD, or accountie hits you hard. Sniff it up and keep fighting even harder. It scares the hell out of them.