A few years back I took a course on Expertise: how experts think, how they become experts, and what it means to be an expert. That course had a huge impact on my thinking. The huge revelation was that "Deliberate Practice" is the only thing that leads people to become experts in any field (Ericsson, 2006). So as the old saying says: "Practice makes perfect". But this practice needs to be "deliberate" which means several things, among them, there needs to be some sort of feedback mechanism (possibly a coach or a feedback of a musical instrument, or even a personal reflection). I always thought that practice is very important, but I never realized that this was really everything. There is no magic pill, no inherent talents, it's pure practice - 10 000 hours of DELIBERATE practice.
Of course there is much more to it than just saying: YOU NEED TO PRACTICE MORE! There needs to be the will to practice (motivation), the opportunity (appropriate environment), and of course there needs to be the appropriate feedback, so that the practice is deliberate. But when it boils down to comparing an expert and a non expert, the expert just put in more time into the field.
Ever since that revelation, I have a completely different view of the world. When I think about how my children learn, how they think, or if I read an interesting article about learning / teaching I go back to that idea, and then it all makes sense.