A related exercise that may be of interest: five levels of "why."<p>Find a willing friend or coworker, and ask them why they did something with a project of theirs. When they answer that, ask them "why" about their answer. Do this a total of five times.<p>After the second "why," they'll probably have to think pretty hard. The fourth or fifth "why" sometimes elicits a "because it's just done that way" or "I dunno" response.<p>Then let them do the same to you.<p>It's a fun exercise.