When Fred Armisen is doing an Update bit that's not going well, that's probably the hardest to not laugh because he is the most fearless performer. Once he did his Native American stand-up comedian character, and the audience just wasn't going for it. But it's this great thing — you don't worry because he couldn't care less. I feel stressed when other people's [bits] don't go well, but with Fred, I've been trained to just go with it and know that for certain people, it's gonna be their favorite thing.
Two things interesting there: 1) The idea of associating commitment and fearlessness. In a way, really committing to a bit is actually just letting go of fear. 2) Enjoying when a bit doesn't go well. As long as most of your stuff works, it can be fun to soak in the occasional misfire.
Here's Armisen in "couldn't care less" mode: