In this year’s class of Fortune’s 40 under 40, you'll find leaders who have won Olympic gold medals, helped developed lifesaving vaccines, launched pivotal businesses, led policy changes, and helped drive their companies forward. What helped them to get where they are today? We asked them to tell us about the best career advice they ever received from friends, family, and mentors. Here are their top 13 tips on how to navigate the workplace, meet your goals, and chart the right career path.

Advice for succeeding in the workplace…

Akila Raman, 39, chief operating officer of the investment banking division at Goldman Sachs

Early in her career, Raman said, a mentor gave her the advice to focus less on what jobs and skills will look best on a résumé and more on the mentors and opportunities afforded. “In my experience who I worked for—and with—has had the greatest impact on my career. The incredible leaders and mentors in the financing and natural resources groups challenged me with stretch assignments and broadened my skill sets through varied experiences.”

Elena Kvochko, 34, chief trust officer at SAP

“The best career advice I received was from my dad, who taught me to create value to others through my work,” Kvochko said. “I have always wanted to work on issues that no one organization can solve alone. Now I am in a position to contribute to solving most complex issues.”

Howie Liu, 32, cofounder and CEO of Airtable

The best career advice for Liu? A mandate from his fifth grade swim coach: Go faster. “While it’s not applicable for me in the pool these days, I’ve come to appreciate how much speed matters in business. This has been incredibly relevant for our teams as we push to execute quickly—in increasingly competitive markets, we have to take calculated risks and move fast.”

Keller Rinaudo, 34, cofounder and CEO of Zipline

People tell kids to focus on what they are passionate about. That’s bad advice, Rinaudo said. “A lot of things we are passionate about won’t get us jobs. Instead, figure out what kind of impact you want to have on the world before you die—then focus on building the skills you need to make that impact. This was my dad’s advice.”

Raj Kannappan, 30, vice president and director of the Center for Entrepreneurship & Free Enterprise at the Young America’s Foundation

Kannappan's best career advice: "Work for someone whom you admire.” Kannappan says he didn’t so much get this piece of advice from someone, as he read it in Warren Buffett’s annual Berkshire Hathaway shareholder letters, his speeches, and other writings. “It didn’t click until I realized I was already working with a team I admired at Young America’s Foundation. Spending time with people I respect makes work and daily life more fulfilling. It makes it that much easier to start each day and have a whole lot of fun.”

Advice for achieving your personal best…

Simone Biles, 24, gymnast

“My parents have always encouraged me to be the best Simone I can be, and to never doubt myself.”

Alison Whritenour, 39, CEO of Seventh Generation

A career coach once told Whritenour: "It’s okay to operate at your 80% at different seasons of your career. If you continue to go at 110% all the time you will burn out and lose what makes you special." Whritenour said it was important for her to hear that it’s okay to give yourself a break every once in a while.

Kate Brandt, 36, chief sustainability officer at Google

From an early age, Brandt said, her parents encouraged her to pick a career that enabled her to leave the world better than she found it. “I plan to share this same advice with my daughter,” Brandt told Fortune.

Jeremy E. Joyce, 29, founder of Black People Eats

The best career advice that Joyce received was from his mentor Jason Thomas, who told Joyce the reason his life felt unfulfilled was that he was not living in his purpose. “The moment sparked a fire in my life that allowed me to dig deep into what is it that I was put on this earth to do,” Joyce said. “That taught me how to serve, which gave me the foundation for becoming an entrepreneur. Work is not something you do—it is something you become. I became myself as I discovered my purpose.”

Trina Spear, 38, cofounder and co-CEO of FIGS

“My cofounder and co-CEO Heather Hasson wisely taught me not to get distracted by what others think and to instead stay intensely focused on what’s most aligned with your purpose,” Spear said.

Advice on building a better future for yourself and others…

Benjamin Backer, 23, president and founder of the American Conservation Coalition

“My parents, who have always been an incredible support system in my life, always told me that if I was going to start ‘something,’ do it when I was young,” Backer told Fortune, adding that his parents encouraged him to accomplish anything he wanted, regardless of his age, and that being young actually was an advantage. “Not only do young people often have relentless energy, but we bring new ideas, different values, and unparalleled passion.”

Fidji Simo, 35, CEO of Instacart

“Diane von Furstenberg shared with me that every day she makes it a point to connect two people who can help each other,” Simo said. “I started doing that, and in addition to being amazed by all the magical things that can result from the power of these connections, it has also resulted in many serendipitous opportunities for my own career as well.”

Hamilton Bennett, 36, senior director of vaccine access and partnerships at Moderna

When it comes to career advice, Bennett always thinks about a song lyric she heard at an important time in her life: “While you’re alive, make tiny changes to the earth.” When you are just starting out and trying to define your space in the world, it can be daunting, Bennett said. “Rather than be overwhelmed by possibility and expectation, make tiny changes. I promise you the world will be better for it.”