When Ronda Rousey was featured on Fortune’s 40 Under 40 list last year, she was undefeated in the ring. But in a matter of months, things changed. The wildly successful 29-year-old mixed martial arts fighter lost to rival Holly Holm at UFC 193 in November and had knee surgery this summer.

As part of our 40 Under 40 coverage last year, Rousey shared with us the advice she would give her 20-year-old self. And that advice might come in handy for her today. “Everything that you think is the end of the world right now won’t even matter to you in two years,” she said.

Every year since 2009, Fortune has asked the movers and shakers of the 40 Under 40 to answer several questions, including “What’s the best advice anyone ever gave you?” and “What advice would you give your 20-year-old self?” Naturally, we’ve received a slew of different answers, but if there’s a common thread, it’s that even the best and brightest business leaders need the occasional pick-me-up.

As we get ready to reveal our newest 40 Under 40 list, here are some of the best tidbits from Fortune’s 40 Under 40 alumni:

“You have to create the quiet to be able to listen to the very faint voice of your intuition.”
Michael Dubin
Co-founder and CEO of Dollar Shave Club
40 Under 40 Class of 2015

“Avoid bad meetings and the tempting ‘inbox zero.’ Skip email on occasion, pick up the phone, and have a wonderful conversation from time to time. Memories count.”
Ashifi Gogo
CEO of Sproxil
40 Under 40 Class of 2015

In Eleanor Roosevelt’s words, “Never allow a person to tell you no who doesn’t have the power to say yes.”
Jessica Alba
Founder of The Honest Company
40 Under 40 Class of 2015

“Find a life partner better than yourself. I would not be where I am without my wife Srishti.”
Vas Narasimhan
Global head of development at Novartis Pharmaceuticals
40 Under 40 Class of 2015

“Things are not ever as risky as they seem. People always overweigh risk.”
Sam Altman
President of Y Combinator
40 Under 40 Class of 2015

“Focus on building knowledge, experience and confidence first. Rewards will come later.”
Karen Fang
Managing director at Bank of America
40 Under 40 Class of 2015

“Anytime you have a difficult decision, imagine yourself as a 90-year-old looking back at this moment. What decision would you wish that you would have made? Go forward and look backward.”
Nick Woodman
Founder and CEO of GoPro
40 Under 40 Class of 2014

“Construct your own definition of success, don’t let the world do it for you. Just because someone puts a carrot in front of you doesn’t mean you have to chase after it.”
Michael Patterson
Partner at Highbridge Principal Strategies
40 Under 40 Class of 2014

“When pursuing your first job, focus on working with great people, and not the job with the highest paycheck.”
Kevin Chou
Co-founder and CEO of Kabam
40 Under 40 Class of 2014

“Underpromise, overdeliver.”
Clara Shih
Co-founder and CEO of Hearsay Social
40 Under 40 Class of 2012

“Take time to master your discipline. Take the nitty-gritty jobs early in your professional life. You will benefit.”
Dolf van den Brink
President and CEO, Heineken Mexico
40 Under 40 Class of 2012

“I’ll speak at an event, and there will be a line afterward, and I make sure I talk to every single person. That’s where you learn. That’s where you get the best idea.”
B. Bonin Bough
Host of CNBC’s Cleveland Hustles and former chief media and ecommerce officer at Mondelez International
40 Under 40 Class of 2011

“Be curious. Ask questions. Find and express your passionate enthusiasm for whatever you believe in.”
Rio Caraeff
Chief content officer at Magic Leap and founder of VEVO
40 Under 40 Classes of 2009, 2010 and 2011

“Don’t be afraid to make heroic failures.”
Tor Myhren
Vice president of marketing communications of Apple
40 Under 40 Class of 2011

“One of my mentors said ‘You’re going to have success in your career, just make sure you never believe your own press, because you’ll stop trying as hard.’ I’ve lived by that advice pretty rigidly ever since.”
Wendy Clark
President and CEO of North America at DDB Worldwide
40 Under 40 Classes of 2009 and 2010