What you call "the talent and the 'knack' for it" is simply acquired skill. Anyone willing to put in the hours of deliberate practice will get the skill. There is no inborn 'knack', except simple stuff such as being taller helps basketball.
Talent is a word with meaning that is separate and apart from experience.
Witness, I ask you, the legion of mediocre talent that fill the halls of Corporate IT. Many of those folks did just fine in their Comp. Sci. programs. However, the talent to create and devise is not achieved by 'practice'. For many -- the curiosity fades and it becomes a 'job'. (For those, the pairing idea might actually help a lot, by the way)
When an individual has _both_ talent and experience, they're worth something. With only one, they're not.
I recommend "The mundanity of excellence" by Chambliss. Here's a scribd link: http://www.scribd.com/doc/2926754/The-Mundanity-of-Excellenc...
"So, anyone who sings (deliberately trying, I'll grant you) for long enough will be a great singer. Anyone who swings a golf club long enough will be a great golfer."