There is an interesting article up on the Behance website that talks about personal "grit" being the most important factor in determining success and achievement in life. More than talent or ability, being able to stick with a task and not let obstacles get in your way is a better predictor of how well you do in school, career, and life.
Angela Duckworth, a researcher at Harvard, sums up the two main qualities this way:
1. "The tendency not to abandon tasks from mere changeability. Not seeking something because of novelty. Not "looking for a change." "
2. "The tendency not to abandon tasks in the face of obstacles. Perseverance, tenacity, doggedness."
In my life, I've seen this in action more than once, where people with a modest amount of talent, nothing extraordinary, succeed because they just never give up. They just work harder than anybody else. And I've seen other people with enormous amounts of talent ultimately fail because they just never stick with anything. They either get bored or they lose interest or they move onto something else.
So when it comes down to it, as it turns out, personal drive is more important than talent. You can read the article here.