It's just more anecdotal evidence of just how long it takes to be truly good at what you do. It's not "reinventing the wheel" (you're not using the expression correctly, by the way). Ira also presented it in an interesting way. How often do you get a successful person willingly showing their failures?
Maybe I used the expression incorrectly. To me, saying "work more and you'll be successful" a hundred different ways seemed like reinventing the wheel. But you're right, it's off. I should have just said how much time do we have to waste with this suggestion. Go work instead of reading about how much working will help you.
Repetition works because we are not all on the same page. We all have our aha moments at different times.