Self-honesty

I was just looking at a few blogs by professional artists. What talent. How does one achieve that level of skill? I have been fortunate enough to find people who buy my work and I am grateful that people think enough of it to purchase it for their homes. But I am not in the same league as some artists out there. What makes an artist develop their work to such a degree of perfection? Is it natural talent? Is it lots and lots of hard work? Is it possible to achieve a great talent by hard work alone? How does one sit down at the table or easel and just practice until one one gets proficient? Where does one find the motivation?