MirrorMask, would you mind sharing the question you made and that he answered?
I asked him what his stream of conosciousness was while he was on stage, and what was going on in his head while performing.
He said something like this, clearly using the Legacy of the Beast show as a template:
"So, I come out, Janick's there, Adrian's there, I jump the monitors, mmmh, sound is good, then I have to change, go and get the sword, then go and get the flag for The Trooper.... all like this, for two hours, and you people don't even notice it because you're all YEEEEEH
. Sometimes people ask me what it's like to play in front of 40K people, well, I don't know, I'm too concentrated"
Basically he's paying attention to every single thing he has to do, and what he will have to do next, so that's what goes on in his mind while he's on stage... what he has to do in that precise moment, and what will come next.