It has become apparent to me, and it might even be true - no matter how much you practise and try, you cannot make up for a lack of talent. You can come close, but you'll never achieve what you weren't born with. Before we all hang our guitars on the wall to gather dust, or start flaming me for outrageously negative statements, let me explain:
First of all, you don't believe me? If it weren't the case, then all you need to do is keep practising and you could be a Tommy Emmanuel/Michael Jordan/Tiger Woods/any leader of their skill. Take Sungha Jung, he's what, 13? I have probably played the guitar for at least twice as many hours as he has in his life - probably a lot more - yet he is superior player to me.
There is that edge, something different happening in the brain, in talented people. Something that isn't learnt, it just is - like being born with the genetics to be two metres tall rather than one metre fifty. But unlike being tall, or short, which is something obvious we can see (and we're happy there is nothing we can do about it), we can't see what is happening inside a brain, and whatsmore we can get pretty close to what those talented people are doing...so why can't we push on a little further to achieve the same?
Fortunately talent isn't everything; I won't try to put a number against it, but I'm sure that an un-talented person (such as myself) who has put in a lifetime of persistence is going to do better than a talented person who hasn't. The hard slog will pay off in the end, thank goodness - otherwise nobody would bother - but watch out, when those with talent start putting the hard slog in too, well, it's lucky we have day jobs, and we're primarily playing the guitar for our personal enjoyment ;)