They all make the same point. The world doesn't owe us anything for showing up. Luck has nothing to do with "success" (often defined as money and fame, success can also mean "getting it right"). It takes work, perseverence, frustration, repetition, persistence, good work habits, and focus to perfect one's craft. And perfecting the craft doesn't guarantee recognition or sales. It only assures we'll get better at the art we produce.
The components of accomplishment are hard work and time. I would add repetition to this list. As Brooks Jensen says in Letting Go of the Camera,
Artwork, if it is worth anything, is about quality -- quality in vision, quality in intensity, quality in life. The process of being an artist is nothing more than the pursuit of quality above all else.Not pursuit of money. Not pursuit of fame. Not pursuit of approval. As Jensen says elsewhere in the same book, a shallow life results in shallow art. A life with depth and quality results in art with the same.