Money on that scale is of a very different character to money as normal people understand it.

It’s more like being a medieval king: to the extent that you’re the shareholder, your wealth is the “nation’s” wealth; your guards are paid for out of your pocket; and you can be drawn into conflicts that lead to you losing everything.

It’s that latter part that I’d be worried about with Musk. He took a very big gamble with SpaceX, and if one more launch had failed in the early years, he would’ve become a mere footnote on someone else’s Wikipedia page. The concern is he might make similar gambles in future.

Depending on how it ends.

Will he be reduced to a mad man shouting on twitter, with nothing left to his name but failed enterprises?

Or will he carve the moon in his image?

The success he's referring to could be the success of Elon's vision, rather than Elon himself.