“It’s a trashy job, but somebody’s got to do it!” That was the slogan for our fledgling Rubbish Runners business, my first foray into entrepreneurship.

When I was very young, our town had little motorized vehicles that zipped up to the top of people’s driveways to pick up trash. But cost-cutting measures eliminated the service, forcing residents themselves to bring garbage cans to the street for collection. My teenage self saw this as an opportunity, and Rubbish Runners was born, charging $2 a week to transport trash cans to the curb and back, a service that would potentially appeal to the elderly, lazy, or entitled.

We didn’t build a sophisticated business plan; it was a simple idea with low operating expenses, a modest marketing campaign (homemade flyers posted in public spaces), and a focus on customer service. I recall spending the summer bicycling around town, lugging plastic garbage cans up and down driveways. In the end, we weren’t particularly successful, but I learned some important lessons: It’s essential to identify the unmet needs of customers. People are willing to pay for services they find valuable. And I didn’t want a career in the garbage business.

Rubbish Runners wasn’t my only character-building odd job. I was also a babysitter and a camp counselor. I manned the drive-through at Bess Eaton Donuts, making coffee and ringing up customers. I was the late-night closer at McDonald’s, responsible for mopping floors and cleaning bathrooms. And I filled orders and worked the register at Papa Gino’s pizzeria. Through these experiences I developed some practical skills, earned a meager paycheck, and became eager to pursue a more stimulating and lucrative career.

Many business leaders also held odd jobs before they built their brands. YouTube CEO Susan Wojcicki’s first business was selling “spice ropes”  door-to-door at age 11. To make extra money in college, Merck CEO Kenneth Frazier raised tadpoles and newts and sold them to local stores. Billionaire CEO of Berkshire Hathaway Warren Buffett peddled golf balls and gum around his neighborhood. Facebook COO Sheryl Sandberg taught aerobics when she was in high school. Amazon founder Jeff Bezos flipped burgers at McDonald’s. Twitter CEO Jack Dorsey went into fashion design and massage therapy. Whitney Wolfe Herd, founder and CEO of Bumble, started a business making bamboo tote bags to help areas affected by the 2010 BP oil spill. Netflix CEO Reed Hastings sold vacuum cleaners door-to-door. Tesla and SpaceX CEO Elon Musk shoveled grain bins and cleaned out the boiler room of a lumber mill. Reddit co-founder Alexis Ohanian washed dishes at Pizza Hut.

Famous scientists also built varied skills and experiences from jobs outside their eventual areas of specialization. Isaac Newton worked as a farmer, Marie Curie as a governess, and Jane Goodall as a secretary. Michael Faraday was an apprentice to a bookbinder; Charles Darwin was an apprentice doctor. Katherine Johnson taught elementary school, Albert Einstein served as a patent clerk, and Mae Jamison was a dancer. Thomas Edison sold candy, newspapers, and vegetables on trains.

Great thinkers and leaders from the past and present held various jobs in their youth, many unglamorous and some unsuccessful. They started their own businesses, sold goods door-to-door, and worked in fast food. They washed dishes and raised amphibians. They taught and danced and farmed. These experiences built responsibility, tenacity, customer insight, ingenuity, work ethic, and character.

And what a gift it is that they’ve shared these experiences so we may learn from them. We learn that there is no singular or straight path to leadership and impact. That it doesn’t matter where you start or where you find yourself today — there is always opportunity ahead. We recognize that no job is beneath any person and that we should never judge others harshly. We appreciate that these varied roles present chances to contribute, learn, and grow. In fact, these very experiences may have fostered the suite of capabilities and perspectives that propelled these individuals to greatness.