Re: Things that go through my head while I'm playing a gig:
About two years ago, I took on the task of playing backing tracks for our 3 piece band via an SPD-SX.
The easy songs have only 3 or 4 segments that repeat in the same manner throughout the song and those are never an issue.
The more difficult ones have 9 or 10 parts that don't necessarily follow a 1 thru 10 pattern. On those, all I am thinking is, "I wonder which pad I should hit next?" Playing the wrong drum part is much easier to disguise than playing a wrong piano/horn/synth part. All I can do is kill it and wait for the next segment to come up.
When I just play drums, all I am thinking is, "This is an easy gig!" and "I wish the front line/guitar players would move around some more and act like they are having fun".