Michael Bloomberg, former Mayor of New York and founder of Bloomberg LP, speaks to the class of 2017 at Villanova University.

In honor of graduation season, CNBC Make It is rolling out the speeches and advice that America's leaders are most excited to share with the Class of 2017. Follow along using the hashtag #MakeItNewGrads. Business magnate Michael Bloomberg, a man worth an estimated $48.9 billion, says that when he was 22, he had no idea what he wanted to do with his career. In a commencement speech at Villanova University on Friday, the former mayor of New York City shared how he navigated the transition from school to the workforce. "Now, if you are sitting out there thinking to yourself, 'OMG, what am I going to do with my life?'" Bloomberg says, "don't worry." "When I graduated from college, I didn't know what I wanted to do. And after I graduated from business school, I still didn't know what I wanted to do."

Michael Bloomberg Ilya S. Savenok | Getty Images

Bloomberg earned a degree in electrical engineering from Johns Hopkins University in 1964. Two years later, he received an MBA from Harvard. The first decision he made after business school, he says, was one of the most important of his career. It's advice he thinks every college graduate should take to heart: Don't take a job based on salary, he says, but on how much you think you can grow at a company.

Take the job you'll most enjoy working at, and then work like crazy. Michael Bloomberg founder of Bloomberg LP, former mayor of New York

After deferring military service during the Vietnam War, Bloomberg took a job in the vault of investment bank Salomon Brothers. The role paid significantly less than other similar opportunities at the time, Bloomberg says, and the work, counting stock and bond certificates, was grueling. "It was a pretty lowly start for a Harvard MBA," he wrote in his 1997 autobiography, "Bloomberg on Bloomberg." "We slaved in our underwear, in an un-air-conditioned bank vault, with an occasional six-pack of beer to make it more bearable." But Salomon Brothers was known for its culture of meritocracy, and Bloomberg felt he could grow professionally there.