Mark Klein calls himself a “stand-up monologist.” He spends a lot of time examining modern society, family and the tenuous process of aging. “I’m a middle-aged man in a youth-obsessed society,” he explains in one bit. “Well, you’re going to get old, too, girls and boys. You’re going to get old, and you’re going to die. And that’s if everything goes well.” His diction is fast, deliberate, and lean — as though he might be the guy with the top hat trying to coax you into his funhouse. He has performed all over the world in his last three decades on the road, as well as made several television appearances on CBS, Showtime and A&E. This weekend, Klein will return to the stage of his home club, The Caravan, for a series of hometown performances.