To be fair I believe we all have this basic bias. For example, when I have a streak of failures, I approach another task with caution, even though it may be simple and normally I'd do it easily. And when I have several successes, I get overconfident and commit to hard tasks (and sometimes even complete them, by a combination of experience, luck, and other factors). Musk had some great successes and believes it is his inherent feature. (Or, at least, this is how he appears.)

The good thing is that we, as humanity, benefit from his successes, but have also deal with his unfulfillable promises, not to mention occasional fits.