Just wondering if anybody has a re-occuring moment that can throw a monkey wrench into a measure, song, set, show, etc. 

Here's my example:

Whenever the groove is really going well, and the band seems locked in, and I dwell too much on "wow, this is going great!" that's when I have a mental flutter and flub something that breaks the magic.

Usually it's when I allow my usually semi-stern drummer face to break out a smile.  For me, enjoying the show too much, (at least outwardly) causes me to break concentration.

Attractive females boogying on the dance floor seems to help me enchance the groove, oddly enough.   

I dont usually mess up but its usually when im just somewhere else mentally or im thinking about the next tune on the list.