17. Max Levchin, Co-Founder, Paypal:

Seems Max didn’t have much think to regret. But as far as he thinks, he should have taken much more statistics when he was in college. He revealed it in an interview with Fortune in the year 2009.

18. Mark Cuban, Chairman, HDNet:

Mark Cuban says, "Professionally, it was not forcefully going after the MPAA [Motion Picture Association of America] and RIAA [Recording Industry Association of America] in negotiations for the DMCA [Digital Millennium Copyright Act]. Another mistake I committed was not applying for patents, but I personally think patents are for the most part worthless and don’t protect your business”, He revealed the mistake that he committed in an interview with Tech Crunch in the year 2011.

19.    Thomas Stemberg, Co-Founder and Former CEO, Staples:

Thomas said that, about two years later than their competitors, they began to deliver. But that mistake cost them over $100 million in sales and $10 million in profits. He also added that, today because of the mistake they committed at that time, their delivery business represents just $2.5 billion. So with that, he was opinion that in the future whenever we plan our business, it will be better if we start off first with the customer and then move towards the cost rather than the other way round. He revealed this mistake in an interview with Inc in the year 2001.