What's left for Roger Sterling? He's tried a younger wife, Don's mother-in-law, and a few exciting (sometimes nude) adventures with LSD. Now he's bored. Is therapy the final frontier? "Turns out your experiences are nothing," he tells his shrink in "Mad Men's" sixth season premiere. "You're just going in a straight line to You Know Where." John Slattery says Roger wishes he was so blasé, and talked to Vulture about what brings out the actor's own moments of existential crisis. For the Roger-Joan shippers, he tries to clear things on that front too.