During his formative years, Jobs worked at Atari for a while under Nolan Bushnell. Bushnell is among the founding fathers of video games. He taught Jobs that if you act like you can do something then it will work. Jobs also learned that "If you pretend to be completely in control then people will assume that you are."
Jobs had this uncanny ability that his friends called the "reality distortion field" using which he would stare at someone unblinkingly and make them do a seemingly impossible task.
Wozniak mentioned that Jobs knew how to talk to a sales representative. Before starting Apple, Jobs called chip makers like Intel to get free samples.
Bill Gates had this ability to be laser focussed on whatever he was working on (he sounds eerily similar to Elon Musk). He was a genius, hard bargainer and liked to flaunt his genius( at least in his younger days ).
When working on a coding project, Gates would work non-stop for two days, sleep for ten hours, eat a pizza and get back to work. He must also have been charming as despite being a jerk (sometimes), he always had a friend with which he would hack on things.
In probably his most important meeting with IBM, Gates looked like an office-boy in his oversize suit. The IBM folks first thought that he looked like a punk kid. However, once he started, he wowed everyone with his insight and calm confidence. However, it was largely an ACT. Gates went to his office and lay on the floor agonizing about his doubts. Moral of the story: If you don't have confidence, FAKE it.