I talk about an observation that's been a recurring theme ever since I started improv class. I've never seen a teacher get so happy when you fail. And when nobody is failing, you're either playing it safe, not thinking fast enough, judging what you're about to say, etc. Failing is seen as a good sign in improv.
The gem that's taught through some of the games you play is how to fail on a microlevel. Then acknowledge what's the worst that can happen. Shrug it off or tweak what you said. And move on.
This fear of failure might be non-existent when you step in the gym or go to Snatch, but it might be raging wildly when you step into a different scenario/environment.
To see how a master of his craft teaches this way of thinking (which is really to get you to not think) is not only a paradox but art I've come to really appreciate.
There's a weird sense of freedom in being able to fail small, fail fast, and fail a lot.