The point regarding apparent differences in martial arts talents, that some posters have mentioned, seems a bit specious to me.
Whilst it may be obvious that two newbies to the sport may exhibit vastly different talents, it may well be he case that the person who seems a 'natural' has previously engaged in activities that require similar skills.
I mentioned this from a teacher's perspective, but let me add to it from a student's perspective. Before doing martial arts, I used a bike to get around town and otherwise I spent most of my life avoiding sporting activities. I did swimming at school, simply because being in a warm pool made more sense than running around in the cold wearing shorts. Despite the lack of previous form, I still found Martial Arts were something that was relatively easy for me to do.
However, when doing dance later on, I used some of my martial arts skills to my advantage. But I should mention that many of my MA colleagues were simply dreadful at dancing. I had to teach my original sensei to count 1-4 when dancing to try and help him dance in time when clubbing as he was so dreadfully out of time. Yet without anyone ever telling me anything I could always dance in time/in rhythm without counting. In fact when I started being taught partner dancing, it was obvious to me that a lot of what I was being taught was simply wrong, despite having far, far less experience than my instructors.
Whilst no-one would argue that physical characteristics have a huge affect on say whether you would be Gold medal material, why do people think brain power/skills do not have the same bearing, despite all the very obvious evidence around us? i.e the entire population who are so vastly different in everything they can do. Even if they have had the same training.