I don't think it's so much a learning disorder as it is a prevelance by society to reward 'visual' and 'memory' types of learning.
^^^^ huh?

I had the same problem in school. Everything was based on learning names, memorizing things and visually watching a teacher show you how something worked. I'd fail miserably cause I'd just naturally rebell against using names that people had made up for things
(stamin?? ..it's the pointy thing on a flower... who's the dummy that came up with name stamin?) I prefered reading books and finding things out for myself. I learned things by naturally understanding a topic as a whole, rather than breaking it down into memorizing small parts of it.

Unfortunately, the education system is geared towards rewarding the visually oriented type of person and failing people who think more artistically.

Anyways... I just think different people learn in different ways.
That's why some students can just naturally pick up on music while others can't even understand basic rhythm patterns.
Some of them 'get' music just by listening to it. They don't understand the mechanics of how it works, but they can figure out for themselves what sounds right and what doesn't even when they're still kids.
Others are more visually oriented... they need it spelled out for them and almost need a mathematical equation in order to figure it out.

I guess the best of both worlds is the person who can learn both ways... however I can only comment on my own personal experience and say that I'm glad I didn't learn any theory until much later. I definitely believe it gave me a deeper understanding of music because it forced me to try things that most students are discouraged from doing simply because their teachers think that it would be too confusing to them to stray from the assigned topics. I was forced into many more years of trial and error, experimentation and listening and feeling rather than reading and copying.