To solve a problem or to reach a goal, you don't need to know all the answers in advance. But you must have a clear idea of the problem or the goal you want to reach.
Bio: Christopher Isaac "Biz" Stone is a co-founder of Twitter, Obvious, Medium, and Jelly. His first startup was Xanga in 1999. Stone co-founded his latest venture, Jelly, with Ben Finkel.