A good portfolio manager knows which companies to keep and which ones to let go. Many a GP has struggled with portfolio companies that cannot meet their value-creation milestones, or raise additional follow-on rounds of capital, or generate target returns in a time span of, say, five to seven years. The faster you recognize those losses, the better it is.”-“As David Cowan says, “Just focus on your top five—the rest is distraction.” The harder part of the investor's discipline is to know when to quit.”-“You have to constantly scan all of those things and be willing to adjust your own sense of what's a reasonable outcome and move the company into a position where it has the maximum chance to succeed. ”-“Time is your enemy: Portfolio companies always take twice as much capital and twice as long to exit. Early-stage companies rarely meet milestones as planned and always burn cash faster than anticipated.