Ok, this is happened 6 months ago. I was learning Bach's Prelude and Fugue in C minor from WTC 1 and I was on the prelude. In bar 19 in the first note of the right hand there is an F. When I learnt it I mistook it for an F# and so stayed with me until near the piano exam period. I didn't realise my mistake until my teacher pointed it out. It took my a while to unlearn the mistake. But these wrong note things mainly happened in my earlier eyars of piano studies.
So, what about you?
JL