When I was 6, I began playing piano. Piano sounds normal, and what writes a C sounds like a C.
After going into middle school, the band teacher decided that I was good with Trumpet. The kind of trumpet I have played(so did most people) were keyed Bb, meaning if I blow into the instrument with the fingering they told me corresponds to the note C, it would rather sound like a Bb. At first nobody knew what I did, and I always read my piece as if it is written for piano, note to score. In the end of the first year, I have learned to play the piece I am supposed to play two semitones than what it is intended.
So I began to completely disregard my scores. I merely looked at it and said, “oh, I start at the first section, stop at the second, etc. and left it in the folder for the rest of the semester. Instead I looked up recordings of that song and at the end it turned out good enough for the recital.
Yep, I learned to play an entire piece by recordings alone because the music scores look strange. In fact if you give me a trumpet piece now, I would probably tell you that this piece is keyed wrongly.
I wanted to start a topic saying “All instruments in an orchestra should be in the same key” and the only thing stopping it would probably be an appeal to tradition.