The animated series “Adventure Time,” now entering its sixth season on Cartoon Network, is the kind of cult phenomenon that’s hard to describe without sounding slightly nuts. It’s a post-apocalyptic allegory full of helpful dating tips for teen-agers, or like World of Warcraft as recapped by Carl Jung. It can be enjoyed, at varying levels, by third graders, art historians, and cosplay fans. It’s also the type of show that’s easy to write off as “stoner humor,” which may be why it took me a while to drop the snotty attitude, to open up and admit the truth: “Adventure Time” is one of the most philosophically risky and, often, emotionally affecting shows on TV. It’s beautiful and funny and stupid and smart, in about equal parts, as well as willing to explore uneasy existential questions, like what it means to go on when the story you’re in has ended.
