I think pretty much anyone can learn pretty much anything.  I don't think people are born to be good at math or science or art.  Most skills can be learned by most people.  But a lot of it depends on things like nature, nurture, personal interests, role models, geography, economics, politics, school systems, teachers, and personal learning style.  Most people can learn most things, but do they want to?  Did they live in an area with a decent school system?  Did their family and friends value education?  There are a lot of variables at play. 

Another thing I've noticed is that learning usually involves a combination of desire, ability, and speed.  I had a friend in school who had the desire and the ability, but not the speed.  He tended to score poorly on tests because he couldn't finish on time.  I had another friend who had the ability and the speed, but not the desire.  Neither friend pursued or succeeded in much education after high school. #education