THE FUSE

When you watch “I’m Chevy Chase and You’re Not,” Marina Zenovich’s spry and fascinating dark-side-of-a-comedian documentary, you hear countless tales of Chevy Chase’s casual cruelty and too-wise-for-you attitude and devotion to behaving badly — or, at least, mouthing off so rudely that it became a form of behavior. If you go into the movie wanting to be shocked and appalled, you won’t be disappointed. Off camera, a lot of comedians have prickly and difficult personalities. But there’s prickly and then there’s the unique drive-by karma of Chevy Chase, a comedian who helped to invent “Saturday Night Live,” who proved to be a singular and hilarious master of ironic barbed detachment, who became one of the most celebrated movie stars of the 1980s, and who was such a famously nasty and unpleasant person to deal with that the word “asshole” followed him around as if it was his middle name.