So I just had a little morning practice. Only practiced 1/4 of the piece today. Played slowly once, not too bad, knew what to play. Tried the second time still slowly...got blanked twice...3rd time got blanked again twice, but in different spots. After that I couldn't even get through the first 2 measures, simply had no idea what to play, could not retrieve any memory of the piece from my head....this is what usually happens.
Had some coffee and went back to the piano. Played fast once, fine...managed to play fast 3 times before I started having small memory breaks. Decided to stop while winning

I wonder if taking such small breaks in practice more often would be helpful. The problem is just that I am so damn lazy to get up from the piano...
EDIT: Or maybe not...went to the piano 3rd time, and now it was like the piece had completely vanished from my head. Couldn't play it at all...After really struggling for a few times I was able to barely get through once in moderate speed and decided to stop. Tried the nocturne and couldn't remember most of the first page on it either and I had no trouble with it yesterday. Decided it's one of those days, better go to work instead...
I wonder if Bach is actually causing brain damage...
EDIT2:
Had one more little practice session. This time started with the Nocturne and had no memory problems at all in the part that I had learned. OT: I also see much improvement on my RH octaves, which makes me very happy. I’m now able to play deeper to the keys as long as they are slow.
I was able to get 15 minutes of focused practice with both pieces before I really had to leave for work. So either it was the raising coffeine level in my system or my theory is right: I should never start my sessions with Bach since it is not good for my brain. I agree that it is good for the fingers, but obviously is dangerous for the brain if not taken on at the right time

Also this might explain why my lessons sometimes are a complete disaster…I don’t get to “start again” until I get into the right mind setting...