"A sense of passion and obsession..."

The BigThink blog has a video of The New Yorker editor David Remnick giving advice to "young journalists." He says what I've heard (and learned) in many other ways: Hope for luck, work like a nut, and obsess about your field.

There's also a mention of having "talent" -- but how do you define that? And if you are a young journalist/writer/artist/wordsmith/whatever you define yourself as, how do you measure and refine your talent?

"Hope that you have some talent almost equal to or equal to your sense of effort," he says. But how do you know if you have talent or are merely a hack who tries really, really hard? Is talent innate or can it be acquired? And what authority can answer this question?

Should we define talent in the same way The New Yorker does?