I think we'll be kidding ourselves if we didn't submit that some people do 'just' understand certain things better, for whatever reason. However, this does not automatically mean that another person cannot reach that understanding.
I like to use my brother and myself for an example. I can think about a project to build and have a pretty good idea how to build it. It's been like that since our lego days. He needs a blueprint, step by step instructions and in-depth diagrams to fully come to grasp with it. Even putting together stuff from IKEA takes me about 5-10 minutes, he'll spend about an hour to two hours.
On the other hand, growing up both studied the piano at the same time and practiced for the same length of time. I just could not get my fingers to play thes notes right. He could run through a sheet of music the first time with very little errors. I would spend a week to just be able to run through it.
So genetically, I think something is there, but the big take away is that, even though we have certain difficulties, He can still build stuff if given time, and I can still play music if given time. Just because stuff may not come as naturally to you does not mean you cannot eventually do it!