Reading old back issues, I came across this editorial from New Scientist, 16 September 2006 (article behind paywall, educational institutions may provide access). The key quote, summarised:

…brilliance in academia, sport, music and many other fields is due only in very small part to innate ability. Mostly it comes through inspirational instruction, a supportive environment and sheer hard work. “It isn’t magic and it isn’t born.”
…
John Sloboda, a psychologist at Keele University, has demonstrated a strong correlation between expertise in music and the amount of time spent practising. The notion that people love doing things because they’re good at them is back to front — they’re good at them because they love doing them and will spend hours practising.
…
For a start, if the aim is to nurture successful adults, creating elite schools for highly intelligent pupils… is a waste of resources because it doesn’t work. More importantly, it gives the wrong message to thiose children who are not selected… it tells them that hoever hard they try, they will never break the mould their genes have cast for them. Unless these children are highly motivated and confident, the chances are they will carry this message with them forever.
More surprisingly, this form of streaming can be disruptive for brilliant children as well, because it makes it harder for them to deal with failure… [it] discourages them from trying things that challenge them and potentially make them look less smart. They tend to develop an inflexible mindset and stick to things they know they’ll succeed at.

The summary of the summary: hard work, not innate skill, leads to success. I’d add a dash of luck (so make your own) and a smidge of networking (because who you know is important).
Discuss.