I play guitar and was in a band for a LONG time and even when I would be on stage I would find myself Dazing and then realize I had no Idea where we were in the song didn't even know if I did my lead yet.
I just played by repetition.
Then other times I would forget the chords and notes for a song I would start to panic.... and I was taught by other Musicans if this happens try to turn your mind off don't think about anything and you will find...... you are playing the song right on the money and if you start to think you can really mess up.
It is quite funny how it can work!
Ps No Drugs or Booze..... you can't play that way!!!!