Kevin Ryan, co-founder of DoubleClick, MongoDB, Business Insider, and Gilt Groupe (among others), speaks with Nick Beim at Venrock about building teams and what to look for in a VC. Ryan advocates taking risks as an entrepreneur, even if it leads to a failure or two. You can learn a lot from unsuccessful ventures and it prepares you for the next thing. They also discuss how entrepreneurial optimism is essential as there will always be rejection and bumps along the way, but it can also cloud judgement when it comes to an exit opportunity. Overconfidence may make you want to pass up a good deal when it comes along.  Ultimately, you have to have fun. It’s what keeps you going.