This post is mostly me thinking out loud, but I'd like to get some others thoughts here too. I would say that everyone does the things they do because of some perceived benefit in doing so and the same applies to learning. There are then two means of "reward" for doing things, intrinsic and extrinsic. I have a hypothesis that those with ASD do and learn things more so because they are intrinsically motivated to do so. Special interests are pursued more because they are generally interesting and enjoyable than because if some external goal or purpose in pursuing them.
Now, this is not to say that NTs are any different up to this point. We all do the things we like. Where I think perhaps a slight difference exists is that NTs can be equally driven by extrinsic motivation. They study hard to do well on a test to get a degree and land the career that will allow them to make tons of money, etc., etc. I know if it's not something I'm really into, I have a REALLY hard time investing myself into it. Furthermore, society seems to place more value on extrinsic motivation. I know people at the university I attend who have studied art, literature, or philosophy and then get harassed with questions like, "Well, what kinda job are you going to get with that?!" As if there is no merit in the mere enjoyment of the intellectual or creative pursuit.
Anyway, that's been my thought here recently. Would appreciate others weighing in.