Several times, I've taken to the skies and exploded. Several times, I've wanted to snatch a Kerbal by his unconcerned cheeks and scream, "Don't just sit there in slack-jawed amazement! Fly this thing, dammit!" But with all that failure and frustration followed intense self-congratulation -- the moment I realized I got a ship shaped like a pizza to fly, or the second I safely returned my Kerbal physicist from a successful Mun (Moon) orbit. Through persistence, trial-and-error, and learning the fundamentals of actual space travel, I somehow met with success. It's the type of success that's intoxicating, and, if you have a penchant for physics or space exploration, completely necessary.