Success and failure are, of course, highly subjective terms. Success, according to what definition? What flavor of failure?

I'd almost be inclined to suspect that Musk says (privately, to his closest confidants) that he's had very few successes and a great many failures.

Now, on the other hand, if one wanted to say that his public persona is often that of a pompous windbag, I'd be hard-pressed to disagree, though I'd hasten to add that (unfortunate as it might be) one almost has to be a pompous windbag in public to get far in business in contemporary culture. We live in the Era of Outrage, after all; "number of people pissed off" might as well be currency.