What Intimidates You?

I was watching the 2005 WSOP a couple of months ago with my wife when she noted how calm Greg Raymer was after he shoved all his chips in the pot and waited for his opponent to make his decision.

She said, "God, is he intimidating!" I was surprised at this comment because Greg seems so affable at the table.

"What makes you say that?" I asked.

"He's just sitting there like he can't even be bothered," she said. It's like he's on his couch watching football instead of playing for millions. He looks like he doesn't care one way or another what his opponent does. I find that to be very intimidating."

That got me to thinking about what would intimidate me as a poker player. I don't know that I'd be particularly intimidated by Greg Raymer's demeanor if I played him. He seems too genuinely decent to be afraid of. And guys like Mike Matasow? Meh. I've never understood why the people he berates don't just look at him and ask if he's going to cry for the cameras again. People like him don't intimidate me. They make me aggressive (which, maybe, is all he's after anyway - an emotional response).

I think the thing someone could do to intimidate me the most is call one of my bluffs with a marginal hand and just kind of smirk as he drags the pot. An understated yet genuine disdain will make me feel like a fool and a chump much more frequently than open disrespect. The call and smirk says "You're transparent to me. I'm actually amused by your childish attempt to outmaneuver me and can barely conceal my scorn for your game, but I will because I want to take all of your money."

So....what intimidates you and why? Ever had someone put force you into a shell? Have you been able to overcome a particular tendency to be intimidated in certain situations? How did you do it?