Looking at the success trajectories of today’s disruptors–from Pandora cofounder Tim Westergren to Wikipedia’s Jimmy Wales–it’s easy to think that they had everything figured out from a young age. But many of today’s success stories learned lessons later in life that they wished they had known as they were beginning their careers. The eight investors and entrepreneurs below share the advice they wish they had gotten in their early twenties.

Tim Westergren: Avoid the risk of not trying and the regret of wishing you had.

Tim Westergren, the founder and Chief Strategy Officer at Pandora, said if he could offer his younger self one piece of advice, it would be to realize from an early age that it’s far more haunting to live with the regret of having not followed your instincts–even when those instincts required a diversion from the beaten path–than to have followed your gut and failed. Luckily for Westergren, he was one of the few who did follow his passions and that pursuit led him to found a company with a market cap of $2.5 billion.

“Be sure to ‘notice’ ideas when you have them. Stop. Take the time to consider them seriously. And if your gut tells you they’re compelling, be fearless in their pursuit,” Westergren said. “For most people, the idea of chasing a personal passion or being entrepreneurial is simply something they don’t think of themselves doing. We’re so programmed to walk well-trodden paths. But, we live life only once. So, rather than avoiding the risk of trying, avoid the risk of not trying. Nothing is more haunting than thinking, ‘I wish I had…’.”

Jimmy Wales: Spend wisely early in life so you can achieve the financial independence to follow your dreams.

Jimmy Wales, the founder of Wikipedia–which according to its own Wikipedia page is a collaboratively edited online encyclopedia–said the advice he would share with the younger generation is to be strategic and thoughtful with expenses at an early age so that you can afford to pursue your passions.

“I think one of the things that most 21-year-old people should do is to recognize now that you can make life choices which control your expenses, and that controlling your expenses is one of the most crucial steps toward the kind of financial independence that you need in order to follow your dreams in the future. Whether it is a change of job, or an entrepreneurial dream, the less you NEED to spend each month, the easier it is to follow those dreams. There are several rules of thumb that can help with this, but one of my favorites is to never go into debt to finance any kind of luxurious consumption. Only go into debt if necessary for some kind of investment, like student loans, for example.”

Bill Ready: Surround yourself with great people and be fearless in pursuit of game-changing ideas.

Bill Ready, the CEO of Braintree–the mobile payments platform for online and mobile commerce that counts companies like Uber, Airbnb, and Fab as clients–shared two key pieces of advice that he wish he had known when he was younger.

“There are two main things I wish I had known when I was 21,” Ready said. “Back in the late 1990s when I was a 19-year-old engineer at Netzee–much like other bright, young, ‘hot-shot’ engineers today–I had this sense that I knew everything, and I didn’t realize the importance of really listening to those who were more experienced. What I have realized since then, is that one of the most important things you can do is to surround yourself with great people, and to listen to them. The second piece of advice I would give is to be fearless. Don’t be afraid to pursue revolutionary ideas, and don’t hold back simply because you’re going up against seemingly unconquerable competitors in your market space. At Braintree, many of our competitors are huge, established companies in the market with market caps in the billions–but we’re not afraid of going after them.”

Alexander Ljung: Realize the power of simplicity.

Alexander Ljung, the cofounder and CEO of SoundCloud–the popular audio platform that has raised more than $63 million in venture funding, according to CrunchBase–shared the importance of learning the power of simplicity in today’s complex world.

“In recent years, T.S. Eliot’s reported quote–‘If I had more time, I would have written a shorter letter’–has stuck with me when making numerous decisions specifically around leadership, design, and product. The advice I would offer my 21-year-old self is to remember that it takes more mental (and sometimes physical) bandwidth to create something simple or communicate something complicated in basic terms, but ultimately, that’s a lot nicer for the user experience,” Ljung said. “It’s not about building every feature or understanding everything the first time around. It’s about creating the best, tailored experience for your community and company. I’d remind myself of the importance to leverage design as a decisive advantage and to not be afraid to challenge people to break down their knowledge into easily digestible, clearer statements.”

Philippe Courtot: Focus on what makes you truly happy.

Philippe Courtot, the CEO and Chairman of Qualys–the enterprise cloud security firm that went public last year–emphasized the importance of doing what makes you happy; pursuing what actually makes you happy ensures that you’ll put the needed energy, time, and resources behind your work.