When you’re interviewing for a job, never find common ground by carping about difficult clients. It’s an easy place to go for creative people, a universal subject that seems like it will unite you in a common struggle with the person interviewing you. It won’t. Unwittingly, you will make yourself look like a whiner. If the interviewer is whining about his tough clients, then let him. But don’t get on the bandwagon. Nod and admit that they’re all tough, and that that’s just part of the game. Remind him of your persistence in the face of adversity, how thick your skin is, and how often you’re willing to bash your head against the wall. You’ll look like a god, not a wimp.