If he wasn't successful he'd probably be quite a different person in practice - he wouldn't have had the money to do most of what he currently does. And that's quite apart from the question of whether he'd have been in the plane-crash that gave him brain-damage, and how that would have affected his personality.

Based on what he does, though? If there was somehow a person who's involved in all the different stuff he is but somehow without getting major recognition or money for him (and that was not in and of itself a notable trait)? Yeah, I get the feeling he'd probably still be interesting.

From what I saw, he's really a fun-loving person. His stories are as much inspiring as they are amusing. Success found him, and helped provide him with the resources to do more of what he already loved to do: tinker with gadgets and teach.