“If you made $10,000 every day, since the day the Declaration of Independence was signed, you would still not have a billion dollars. He [Elon] wants that times fifty.”
It has been ~90,561 days since July 4, 1776. Multiplying that number by $10,000 results in $905,610,000.
I don’t think most of us can grasp how much money a billion is, let alone fifty.