just "mmm" or if you prefer "sum nub" is fine
@ Fried Rice,
I didn't make it especially clear, but I meant all of those things in some combination with each other. For example, someone might not be a quick learner, but put in a lot of practice and experience, while another might just be very smart/flexible thinker and not require as much experience
Also, what you do not consider hard work, I bet many of the people who aren't at a very high level would consider hard work (single spacing through replays, for example, may seem like nothing to you but many people lack the patience for it).