Your 20s are a time for figuring out your place in the world.Mistakes are unavoidable, but the truly successful learn from these setbacks and move on all the wiser.We asked entrepreneurs, including billionaire "Shark Tank" investor Mark Cuban and the cofounders of popular retailer Warby Parker, to share the most important lesson they learned in their 20s.Mark Cuban, "Shark Tank" investor and owner of the Dallas Mavericks, learned that any limitations on personal growth are self-imposed.The billionaire investormade the biggest deal of his life when he sold his company Broadcast.com to Yahoo for $5.7 billion in Yahoo stock in 1999.In his 20s, Cuban developed the all-encompassing self-confidence that's made him successful. He learned that, if he stopped making excuses and got to work, "with time and effort I could learn any new technology that was released."Neil Blumenthal and Dave Gilboa, co-CEOs of Warby Parker, learned that you should never cut corners.Blumenthal and Gilboa cofounded hip, affordable eyeglasses retailer Warby Parker with Andrew Hunt and Jeffrey Raider in 2010. Last June, the company sold its millionth pair of glasses and is now expanding its brick-and-mortar business in addition to the ecommerce model that made it famous.Blumenthal and Gilboa agree that part of the reason their young business has become so popular is because they learned every decision matters at every stage of your career."No matter what you're doing, you should always try your best, especially early in your career," they say. "How you do anything is how you do everything. No matter what task you're faced withlarge or smallalways seek excellence."Jessie Goldenberg, founder of Nomad, says she learned that huge risks are sometimes worth taking.Goldenberg graduated from NYU's prestigious film program in 2010 and got a job working at CBS. It seemed as if her career path was set, but she considered the dream she had of opening her own fashion boutique. Lacking the funds or credit history to make such an investment, she instead raised money to start her own fashion truck, a mobile fashion retailer she named Nomad.Nomad hit the streets of New York City in 2013 and Goldenberg says she broke even by the end of the year. She's been successfully working on growing Nomad's exposure and profits since."One thing I've learned is that your 20s are a time to take and embrace risks," she says. "I'm living proof that it's possible to be 'livin' the dream' and be successful. With no family to feed and no dependents counting on you, your 20s are without a doubt the years to take a leap and pursue your passion!"See the rest of the story at Business Insider Click here to read full news..