Mental performance and ability are directly correlated to one's own success - just look at society's obsession with IQ tests and other assessments of mental aptitude. This idea that mental performance ties directly to my future outcome has led me down some interesting paths and literature (for instance, this neat article, or this blog post) in the aim to increase my own mental performance.
However, as much as brain hacks and other tricks may help you increase your brain's horsepower, the most important thing is to test the bounds of your mind and continually push those bounds. Mathematics is a really good example of a tool that will allow you to expand your mind and mental ability and thus success in life (see the foreword in this paper).
This doesn't mean that if you don't like math you're condemned to not be successful, rather that mathematics ability is a decent proxy for mental capacity and thus future success.
What does it take for someone like Jeff Bezos, or Barack Obama, or Aswath Damodaran to be successful?
There are obviously many variables at play but all these people have the capacity to think deeply for prolonged periods of time. Deep thinkers are able to handle the intricacies of a problem, think about it in an abstract manner, reject one's own desire to give up, and push until a solution has been found.
So it seems plausible that in order to expand your mental ability all it takes is a bit of patience, persistence and desire to learn increasingly complex concepts.