Burrell was hired into Apple in February 1979 as Apple employee #282, in the lowly position of service technician, one of the lowest paying jobs at the company. Even though he'd been doing genius quality work as a hardware designer on the Macintosh project for a while now (more than nine months), and he was even filling in for Steve Wozniak on the low cost Apple II project, he still wasn't officially promoted to engineer as he requested, which was getting pretty frustrating.
Burrell started thinking about what it would take to get promoted. It obviously wasn't a matter of talent or technical skill, since he was already far more accomplished in that regard than most of the other hardware engineers. It wasn't a matter of working harder, since Burrell already worked harder and was more productive than most of the others. Finally, he noticed something that most of the other engineers had in common that he was lacking: they all had fairly prominent moustaches. And the engineering managers tended to have even bigger moustaches. Tom Whitney, the engineering VP, had the largest moustache of all.
So Burrell immediately started growing his own moustache. It took around a month or so for it to come in fully, but finally he pronounced it complete. And sure enough, that very afternoon, he was called into Tom Whitney's office and told that he was promoted to "member of technical staff" as a full-fledged engineer.