Sorry of this is already said, I just reader online the first page.
There is a theorie that of you train more than 10.000 hours, if it's in sprinting, or playing music, you can be good at it. But you need to have feeling about it. I would never become a good sprinter like Usain Bolt, because I don't have that body. But if you look at Usain Bolt, they say it's the fastest man on earth, not really, he is the greatest at 100, 200 and if he started running 400 meter (he was to lazy and it was harder for his body to practice) he would also be good at it. But from a distance of 800 meters he wouldn't win, because he don't have the body for it, so he is not the fastest man on let's say 1500 meter. He is also been born on the right place on the right time, Jamaica is an athletic island. I'm living in the Netherlands, we have good swimmers and good ice skaters, (also athletics) maybe there are also good swimmers and ice skaters on Jamaica, but because it isn't a sport there they would never be discovered because they started track and field or stuck at it and just started a "normal" life, working get children (what's normal). If Usain Bolt was born on an different place in the world, where he can't started sprinting we would never heard of him, maybe in a different sport, but I don't think so. I think soccer players like Ronaldo and Arjen Robben would also be great sprinters, but they start playing soccer. How many great cubers are there in the world that never started cubing, because they weren't on the right place on the right moment? Or they givin up? Churandy Martina, a Dutch sprinter (100 and 200 meter) from Curaçao started at the same time as Usain Bolt and is still in the top of the world. At his fourth Olympics in Rio he said he saw many sprinters come and go, his thoughts about it is because a lot of them givin up, because it's hard working to stay in the top and it cost a lot of money. We now have Dafne Schippers (just god bronze on the 100 meter and hopefully she wins at the 200 meter in a few days) but she is the first great Dutch female sprinter in the Netherlands after Fanny Blankers-Koen. Because she started sprinting, like I said earlier, if she started cicling, soccer, swimming, or ice-skating, we probably would never hear of her Maybe she is also good at a sport that we don't play in the Netherlands, but because she is born here she does sprinting, so she can't change or set new world records at a whole different sport like Usain Bolt chances the track and field sport.
Back about cubing, I think it has to be a sort of genetics, and practice enough and being on the right place at the right moment. I'm just restarted after 3 years, and have finally become sub 20 avg. If I look at video's now I'm just understand everything better, one because my English is better, but two because, if I look back, I didn't understand the logic behind it, and still I think so. I know people with a very low IQ, I believe I can learn them to solve a Rubik's Cube, but they would never get as fast as the top, even if they train more than that 10.000 hours. On a school test of me my spatial awareness (?) was like 3/4 out of 10. I think that's doesn't help cubing much. I'm never be intuitive even with F2L, that doens't help speedcubing also. A boy I learned cubing was a fast learner, he saw the logic behind it directly. Sadly he didn't want to solve it as fast as he can. He just liked it to solve it in front of the tv. But I still think he would be a fast cuber. And what Feliks always says people on school have the most practice time, if you become older you have to study, going to work, maybe get children. So my conclusion is, genetic, practise, and being on the right place on the right moment. What if Max Park and Feliks Zemdegs started at the same time with the cubing community and record, competition when Feliks started. I think it is possible it would be a two battle like Usain Bolt and Justin Gatlin, but than a bit friendlier. Or what if Feliks just started last year? Probably the world records where been very low so he never could get the 100 world records, probably not even 20/30. But there both another discussion.