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: Joseph Leonard Gordon-Levitt is an American actor and filmmaker. As a child actor, he appeared in the films A River Runs Through It, Angels in the Outfield and 10 Things I Hate About You, and as Tommy Solomon in the TV series 3rd Rock from the Sun.