JohnCW I believe people are capable of achieving anything they set their mind on, with one exception. And that is the Arts.
I agree with you, however, respectfully, I'd like to add one other exception: rhythm. I have personally met people who were absolutely "rhythm-deaf", to the point where it was almost baffling how they managed to put each foot in front of the other evenly. And that was not for lack of trying, both on their part and the part of the teacher trying to teach the basics. I'm not even talking about syncopation or other "intricate" patterns. It was simply impossible for them to play a rest at the beginning of a measure, no matter how often it was explained to them that they should not be skipped.
If I hadn't met such people personally, I would have wholeheartedly agreed with you... but I just wanted to throw this additional exception in
And also, I realize this is only a side remark that doesn't have much to do with the topic at hand