It's impossible to get everything right when you're just starting out. The most successful CEO's and entrepreneurs have experienced setbacks, even failures.
Luckily for us, they're willing to share their mistakes as well as the lessons they learned.
Here's the best advice that Richard Branson, Jay Leno, and nine other leaders in their fields would give their 20-year-old selves.
Daymond John, founder of FUBU and investor on ABC's "Shark Tank": Work for love, not money.
"There's a great saying: Money is a great slave, but a terrible master," John tells CNBC. "I would tell myself, 'Don't do it for the money — do it for other reasons and the money will come. And if it doesn't come, you won't suffer.'"
Jack Dorsey, CEO of Twitter and Square: Find a healthier work-life balance.
"When I was young, I didn't understand the value of exercise or health and how that affected my intellect," Dorsey says. "I think it was useful for me to go to all the extremes to find the balance I have now, but I wish I focused more on being healthier in the past. A healthier lifestyle ultimately makes me more creative and allows me to think more cohesively."
Jay Leno, comedian and host of CNBC's "Jay Leno's Garage": Make the same mistakes.
"Do exactly the same thing, because every mistake you made will give you empathy for other people that make the same mistake," Leno tells CNBC. "You learn a tremendous amount from the mistakes.
"People who don't make mistakes get sort of cocky and start to think of themselves as better than others. So, yeah, I would make the same mistakes all over again."
Richard Branson, self-made billionaire and founder of The Virgin Group: Everyone should have a second chance.
"I am not the person I was 42 years ago. I am not even the person I was two years ago. We all change, we all learn, we all grow," Branson writes on LinkedIn. "We all deserve a second chance.
"Next time you have the opportunity to give somebody their second chance, don't think twice."
Robert Herjavec, founder of Herjavec Group and investor on "Shark Tank": Dream bigger.
"When I was younger, I didn't understand that people could start their own business. ... I didn't know how to translate my people skills into a career I would be passionate about. At 22, I just didn't get it," the entrepreneur writes on LinkedIn.
"Since I did not know how these things were done, I could not understand how to make them happen. If I'd known I could do these things, I would have done them sooner."
Lloyd Blankfein, CEO and chairman of Goldman Sachs: Chill out.
"There's not a sport, there's not an activity, in life where if you have a really hard grip, you're actually better," Blankfein says. "Whether it's baseball or golf or kicking a ball, the looser you are, the further the thing goes. If you're tight, you're not necessarily better."
Suze Orman, author and financial advisor: Take your time.
"When I was 22, I piled all my belongings into a Ford Econoline van. .... My first job after arriving in Berkeley, California, was helping clear away trees and brush. That was followed by a seven-year stretch of waitressing," Orman writes on LinkedIn. "It wasn't until I was 30 that I landed a job — as a stock broker trainee — that put me on the path that leads directly to where I am today.
"I am not going to suggest that every 22-year-old take eight years to find the path they want to pursue. But at the same time, I hope you are kind to yourself. That you give yourself the time and space to figure things out.
"That's not a license for laziness. I worked, and worked hard, in my 20's. And I wouldn't trade the experiences I had during that time."
Jack Groetzinger, co-founder and CEO of SeatGeek: Don't expect things to get easier. Enjoy what's hard.
"When you're in the thick of the tough parts of building a company, you'll tend to think, 'As soon as we get to X, everything will get easier.' That's usually wrong," the CEO tells CNBC. "There will always be more. There's no magical hump, after which you've made it. Build and live for the long haul."
Jim Weber, CEO of Brooks Running: Master the soft skills.
"I have no regrets, but I would say, develop yourself as a leader of people and as a developer of people," the CEO of Brooks tells CNBC. "I wish I had done more work on human psychology, relationships, and becoming a more empathetic leader. That's a skill-set that I really focused on in my 40's."
Chris Fanini, co-founder of Weebly: Choose your friends wisely.
"The people you surround yourself with is really important," the co-founder of Weebly tells CNBC. "There's a saying that you're the average of the five people you spend the most time with, and I think that's very true."
Dani Reiss, president and CEO of Canada Goose: Think big.
"I would tell my 20-year-old self that the market is bigger than you think," the CEO of Canada Goose tells CNBC. "I didn't plan to get involved in the business — it's a third-generation family business and I wanted to do my own thing — but I ended up working here for many reasons.
"When I did get involved, we were a very small company, and as we grew, I was amazed with how big we were getting. In hindsight, I realize, the marketplace is quite big, and the potential is quite big, too."