So lately I've been composing a lot for my music class. I use the program Sibelius for notation. In Sibelius, there are 2 ways to enter in a note: you can either click on the stave where you want the note to be, or you can type the note name on the keyboard.
Being a fan of keyboard shortcuts in general I decided to type note names. But I was (and still am) really, really bad at it. For a few days, I thought I was just spacing out or tired or something, because I only typed the note I intended to about 30% of the time, and was constantly adjusting everything to make up for my mistakes.
But then I realized that each time I typed the wrong note, I typed it using the finger that would have fingered that note on the violin. So if I mean to type "F", I'd go for "D" instead, because in standard typing, "D" is typed with the middle finger, which is the finger for "F" (in the right octave of course).
Interestingly, this happened no matter what instrument I was writing for, or what clef I was using. Even if I was writing in viola clef - which is annoying for me to read - I would still make the same consistent mistakes.
Once I realized what was going on, I started thinking very carefully before typing each note. "Ok", I'd say to myself, "you want a 'A', so you'll have to use your pinky to type it". And then I'd go right ahead and get it wrong anyway. My brain just didn't want to be rewired.
This is related to another brain quirk that shows up in my mind, kind of like a lost traveler, ever once in a while: I'll be drifting off to sleep, and thoughts will be flowing through my mind. Somehow, in my sleepy state, I'll want to *play* the thoughts on my violin - sometimes it seems as though I should spell each word in notes, and sometimes it seems like each word should have a distinct pitch. Either way, after a few minutes, I realize that my fingers are moving, and that I'm trying to "play" something... but it never works, because obviously the musical alphabet only goes to G. After a few confused minutes, I wake myself up and laugh about it.