I feel like at least some of Steve’s later personality has to have been influenced by interactions such as the one with Bill Atkinson, where he was told rounded corners were "incredibly difficult" to program, only to come up with an implementation a mere 24 hours later. A lifetime of such interactions, such as the one with Larry Kenyon, might have taught him that people aren’t going to do anything (unless he really really insists) and consistently lie to him.