I suppose some of it is also not dark at all, and is simply funny. Here's another excerpt:

"If you're informed that someone or other is speaking ill of you, don't defend yourself against the allegations, but respond by saying: "Well, he must be unaware of my other faults, otherwise these wouldn't have been the only ones he mentioned."

It's stated a bit differently, but this is effectively the exact tact taken by Eminem's competition-winning rap in 8 Mile. "These guys think I'm bad? They missed all this obvious stuff, let me lay out all my faults for you."

Reminds me of Lincoln being called "two-face" by Douglas and replying “If I had another face, do you think I'd wear this one?”

Self deprecation can indeed be disarming. But it must never cross the point of eliminating self respect. That's when you go from easy going to pure loser.