We're taught at an early age to make everything perfect in the practice room; every single articulation, every fingering you write in your sheet music, etc. I can tell you that this is something I think about often and it can stress me out more than it needs to. Taking risks while you perform is an important part of a musician's development because it's what makes it human.
Musicians who take risks don't let little things get in the way of the bigger picture. But on occasion, it happens to the best of us. We work very hard for a performance, to try and make every little thing perfect, and we do a tenuto or glissando to a note and end up falling flat on our face. And you know what, that's okay! People much rather see you and hear you perform as a human being rather than a robot. But at the end of the day, your friends, family and audience, they're there to support you. They want to see you succeed! Mistakes on stage shouldn't matter because at the end of the day your audience is there to listen to what you have to say.