Have you ever been passionate about something, and yet satisfied with yourself in that pursuit?

It seems to me expertise is the result of a deep dissatisfaction with one’s skills in a given area. If someone is great at art, science, language, sport, or any other field, it is because each goal is never enough. They constantly want more.

Have you ever felt satisfied with your abilities in a given field, while retaining your passion for it?

The only exception I can think of is Francis Crick, who after co-discovering the structure of DNA, left the field he helped create to research neuroscience instead.