It is desire (and a litte bit of talent, maybe)

If you truly believed you didn't have any artistic ability, you wouldn't have any desire to paint. It's that desire, combined with persistence and the systematic learning of painting techniques, not talent, which make an successful artist.

"Everyone has talent at 25. The difficulty is to have it at 50."

“What distinguishes a great artist from a weak one is first their sensibility and tenderness; second, their imagination, and third, their industry.” – John Ruskin