After launching Netscape 20 years ago, Marc Andreessen has had a remarkable second act as a successful and prolific venture capitalist. His firm's portfolio includes some of Silicon Valley's most enviable investments, including Facebook, Airbnb, Twitter, Jawbone, Lyft, Pinterest, and Zenefits. On Wednesday, the super VC and avid Twitter user spoke with Bloomberg TV's Emily Chang at Salesforce's Dreamforce conference in San Francisco, revealing to the audience some lessons he tries to instill in the startups he invests in....