Yes and no. He did all those jobs, but as CEO so he would have a first hand understanding of the business he was taking over. He didn't start out doing that and work his way up.
Years ago, Bob Graham, when he was running for the Governor of Florida, had a pretty good little idea during his campaign, he worked one day at a job in all 67 Florida counties, and he wound up getting elected.....didn’t particularly care for the guy’s politics, but I liked him as a Governor, although I was disappointed with his Senate career.
Even still, back then, the culture of America was drastically different. Back then if you had the work ethic and right skills, you could move up; these days single mothers with six kids from a variety of lovers gets preferential treatment over single, smart, self disciplined people.