When Matt Mohlke was 24, he wrote ten things on a bar napkin that he wanted to do during his life. Partying with comedian Chris Rock at the Sundance Film Festival was not on the list, but then again neither was the 3,274-mile journey down the Amazon that routed him there. Mohlke was at the Sundance Film Festival to introduce Big River Man, an award-winning feature film in which Mohlke, who lives in Fountain City, Wisc., plays a cornerstone role. But Mohlke isn’t an actor. He