To solve some problems, you need the assistance of an adult. Just ask Marty McFly, the teenage protagonist of "Back to the Future."
Besides being one of the best time-travel movies ever, "Back to the Future" also reminds us that most teens wouldn't make it to adulthood without some grown-up intervention and direction -- no matter how all-knowing teens think they are.
In Marty's case, he never would've gotten back to 1985 without Doc's guidance. Yes, it's pretty unlikely you ever needed help time traveling when you were a teen, but chances are you at least asked for an adult's advice about study habits, the opposite sex, football or something else. You could argue that it was Doc's fault Marty was stuck in 1955 in the first place, but things turned out for the better for Mr. McFly and his family after Doc intervened (at least until the sequels).