Amazon founder and billionaire Jeff Bezos made reference to his first job working at McDonalds on Sunday, days after a job advert posted by him in 1994 for the "first job" at the technology company went viral.
Mr Bezos posted a picture on Twitter on Sunday, showing him with a meal from the fast food chain.
He worked at McDonalds when he was 16, and later graduated from Princeton University.
"You can learn responsibility in any job if you take it seriously," Mr Bezos told Cody Teets, author of Golden Opportunity: Remarkable Careers That Began at McDonald's.
"You learn a lot as a teenager working at McDonald's. It's different from what you learn in school. Don't underestimate the value of that."
Last week, an advert posted by Mr Bezos dated August 22, 1994, and titled "Well-capitalised Seattle start-up seeks Unix developers" was posted on Twitter as Amazon's first job listing.
The company, now the world's biggest online retailer, was created a month earlier as a book seller.
Mr Bezos wrote that he wanted the developers to "help pioneer commerce on the internet", and he was not seeking average-performing workers, but exceptional candidates.
"You must have experience designing and building large and complex (yet maintainable) systems, and you should be able to do so in about one-third the time that most competent people think possible," the ad said.
"You should have a BS, MS, or PhD in Computer Science or the equivalent. Top-notch communication skills are essential. Familiarity with web servers and HTML would be helpful but is not necessary."
Mr Bezos also outlined the kind of workforce he was seeking to build.
"Expect talent, motivated, intense and interesting co-workers," he wrote.
The successful candidates were expected to move to the Seattle area, and compensation would include "meaningful equity ownership".
The advert noted at the foot that Amazon was "an equal opportunity employer".
Amazon's market capitalisation currently stands at $1.33 trillion. Its global workforce, including part-time employees but not including contractors and temps, was 1.52 million at the end of June, according to Statista.
Amazon reported a second-quarter net loss of $2 billion as the company faced an unfavourable effect from changes in foreign exchange rates throughout the April-June period.
Mr Bezos, 58, is ranked as the world's richest person behind Elon Musk, with a net worth of $154bn.
Last year, he travelled into space on board his company Blue Origin's New Shepard rocket.