He seems to be a really hardworking and compulsory guy who does not only push others but also himself to the extreme. As his wife quoted "He is the worse kind of enemy you can have" etc... But people comment him to be nicer than Steve Jobs. He likes to reads a lot ^^^^ seriously a lot^^^ in his childhood. And he seems to be very good at self-learning as he acquire the knowledge of rockets by self-learning. His Xspace inspiration seems to come from the his childhood fantasy about outerspace inspired by the various science fictions he had read. But I'm not sure about where does he got his idea of paypal --- He cultivate the business idea by first join an internet company and then somehow get the idea of online banking after talking to people in london doing finance??, then scoop people ( can't recall who are they) to join the ideas. People think he is crazy for coming up with the idea because by the time they don't expect people to trust online banking at all. But he has the gut the push through various regulatory blockades and communicate/preach to people about the value? of online banking.
His model of success seems to be :
read a lot--> get your world views settled and firm--> study something that makes you smart and you are interested in --> find a company and works seriously hard-->excavate something seems profitable-->work hard to bring that idea to reality -->cashed the money
Repeat the above process
While zoom in, to address why he could achieve his goal, besides his smartness, one book to recommend is "the one". Productiveness comes from the purpose you have. The author of that book have an annalogy as the productiveness we generally see from a person is actually the tip of iceberg, while the burried pard is the purposefulness/ concentration. So, your productiveness is not sth real but the manifestation of your purpose.