A young Bill Gates.
Doug Wilson/CORBIS
If news reports are right, something like 75% of today's college and high school students won't do something this summer that I once thought was second-nature. They won't be getting summer jobs.

This might be a bad trend — with kids missing out by not working at real jobs during the summer (as opposed to career-track internships and enrichment camps). If that isn't enough reason to reconsider summer plans however, there's another.

Some of the most successful people we admire in leadership and entrepreneurship followed the summer-jobs path.

Here's how 10 of the most amazing entrepreneurs — including Bill Gates, Warren Buffett, and Jeff Bezos — spent their spare time and summer vacations. (Bottom line up front: They worked.)

1. Bill Gates

It won't surprise you to know that Gates had a summer job as a programmer for defense contractor TRW, but he also spent a summer working as a congressional page in Washington. This isn't exactly a glamorous job, and it wouldn't seem to have much to do with starting Microsoft. However, it could have sparked an interest in public policy that led him to launch the Gates Foundation.

2. Warren Buffett

Long before he was a professional investor, Buffett spent his spare time working as a salesman, running a paper route, selling chewing gum and bottles of soda door to door, and detailing cars. According to reports, when he filed his first tax return in 1944, he deducted the cost of the bike he'd used on his routes.

3. Michael Bloomberg

This might be my favorite entry on this list. Before he started a gigantic media company and was elected mayor of New York City, Bloomberg paid his way through Johns Hopkins University by working as a parking lot attendant.

4. Thomas Edison

What is it about selling candy — not just Buffett, but Edison, too? He didn't exactly come from money, and it was long before perfecting the light bulb or starting the company that would eventually become General Electric, but Edison first made money by selling newspapers and candy on a train.

5. Daymond John

Back to more modern-day entrepreneurs, the founder of FUBU spent his summers in high school as a foot messenger, "delivering packages all over the city," he explained in an interview. "At age 16, it helped broaden my horizons and introduce me to completely new parts of the world that were right in my backyard."

A young Michael Dell.

6. Michael Dell

You probably know that Dell founded his namesake computer company out of his dorm room at the University of Texas at Austin, but his first job? Washing dishes at a Chinese restaurant. He also sold newspapers, and reportedly made enough money to launch his computer company.

7. Henry Ford

As a child, Ford's father gave him a pocket watch, which he took apart and reassembled, thus developing both his interest in machines and his reputation as someone who could work on them. He was expected to take over the family farm, but instead became an apprentice to a machinist.

8. Andrew Carnegie

Carnegie was born in Scotland and moved with his family as a child to Pennsylvania, but they never had much money. He went to work at 14 as a "bobbin boy" in a cotton mill, where his job was to work six days a week changing thread spools on dangerous, fast-moving machinery.

9. Alexander Ljung

Speaking of dangerous work, I love this story about the founder of SoundCloud, Ljung, who said in an interview that he worked two summers during school at a construction site, "assisting with fitting ventilation systems." Besides being surprised at how early construction workers start their days, he said the experience taught him that "any system can always be improved."

10. Jeff Bezos

Bezos, according to one report, spent summers when he was growing up living and working on his grandparents' ranch in south Texas, "laying pipe, vaccinating cattle, and fixing windmills."