I've always disliked the term "talented".
It implies that things come to you naturally and without any effort, while in reality the people that are considered extremely talented rarely get to the top without any practice. And the 'rarely' is an understatement. I've never seen anyone reach the top without effort. Not ever. I dislike how 'not having talent' is often used as an excuse for not being good at something, while in reality the only real reason that keeps people from accomplishing things is not working hard enough for it. And sure, not working hard enough can have its reasons. Very valid reasons like having different priority's in life, not having enough time next to your school, job or family life, or even battling an illness. It doesn't change the fact that you're capable of doing it.
I always tend to compare art (or any craft in that matter) with running a marathon. Anyone that's not severely handicapped could run a marathon, but it takes a lot of dedication and hard work. Professional marathon runners are training for months, if not years. They dedicate a huge amount of their time to running, even if it means they have to cancel other appointments because they need to train. They're often left exhausted after their big run -- meaning it doesn't come easily for them either
Why will some people run a marathon and others will never do it? It's because some people care and others don't.
Art is no different from running. Motivation is key here.
The reason why most artists are good at art, is because they practiced. Sure, some people have a genetic predisposition. They might be born a bit more creative, have a better hand-eye coordination, or sharper senses that allow them to see and feel more than the average human. Kids like those like often like to do art in their early years. They're good at it, are praised for it by their teachers and parents, and the boost in self esteem that comes with that might keep them drawing for years. This opposed to the people that don't have that genetic predisposition. All they see it how bad they do in comparison to their classmates, and eventually that often discourages them to quit doing art. Both of them could make an amazing artwork if they really set their minds to it, though.
Drawing, writing, and all other forms or art are learned skills. Nobody knows how to draw the minute they are born. Hell, most kids under 5 years old haven't even learned how to write.
In our early years we learn a lot of things, and the way we're build has a lot to do with how we develop. By praise and comparison with classmates we'll soon learn to distinguish between activity's we like and we don't like. Because what kid doesn't like to be praised for something he does well? We learn to invest in the activity's we like, and set aside those activity's we don't like. The kid that was praised for his beautiful art is likely to keep drawing during his teenage and adult years. The kid that was bad at doing art quit doing art after grade school and invests his time in doing something he's better at.
It's said that any craft can be done reasonably good when spend enough hours doing it, and we start accumulating these 'hours' very early already.
By the time we reach adulthood there's a huge gap between the person that kept drawing all through high school and the person that quit drawing after kindergarten because he didn't believe he was any good at it. And this is the point where some people are perceived as talented and others are not. In reality it doesn't have to do so much with talent, but more with a huge gap in skill.
Do I rule out natural talent entirely with this? No... I don't think it's that simple.
There are genetics at work. Some people are more intelligent than others and learn with more ease. Some people have body's and brains that are better adjusted for certain tasks. Some people need 10.000 hours to master a certain craft, while others need a bit more. Just like anyone could run a marathon, but not everybody could do it in record time. The same thing goes for art. Not everybody can become an truly outstanding artist, but most people will be able to do some really amazing work with the right amount of practice.
You just need to keep yourself motivated.