First, I wouldn't say I feel none of those things. I'm certainly aware of when I've made a misstep, but probably more than anyone else is.[1] I have what I think is the expected, rational amount of anxiety: I don't want to mess this up because I want to help our company close a deal. That's 99% of it, though. I'm not so much worried about making myself look bad.

Second, your analogy of a concert? Spot on! Yes, that's exactly what it's like for me. The way I've felt after being on a literal stage is the same as I've felt after leaving a figurative one: "Whew, nailed it! I'm glad that's done! Now let's go play some video games for a while."

[1] Someone asked me if I remembered every time my colleagues said something awkward. No, of course not. Well, that's how much they think about the mistakes that I've made. I take comfort in that.