Between them, Diane Keaton and Carrie Fisher have forgotten more Hollywood gossip and scandal than the most creative tabloid editor could invent. In 1977, they became stars in roles they would never quite escape: Keaton as Annie Hall, Fisher as Princess Leia in Star Wars. Since then, they’ve lived out their checkered careers and romances more or less in public, a state of affairs that was perfectly normal to Fisher, the daughter of Debbie Reynolds and Eddie Fisher but utterly alien to Keaton.

Fisher’s memoir Shockaholic, the follow-up to her successful autobiography and one-woman show Wishful Drinking, is similarly witty, ramshackle and outrageous. In order to regain her shaky sobriety “after sleeping with a senator, and waking up next to a dead friend, and celebrating Michael Jackson’s last Christmas with him and his kids,” she undergoes electroconvulsive therapy, the still-shocking shock treatment that’s a last resort for people “in sufficiently agonizing shape.” ECT turns out not to be bone-snapping torture but mind-sapping release; the therapy is “incredibly hungry, and the only thing it has a taste for is memory.” The book is therefore Fisher’s attempt to preserve her best stories before they vanish, and they’re told with the buttonholing urgency of a drunk at a society wedding, who knows things you wouldn’t believe about all these well-dressed people who act so refined.

There are stories from Fisher’s unreal childhood and from her friendship with Jackson (whose less-than-scrupulous doctors and hangers-on come in for a timely beating). There’s one about bonding with her one-time stepmother, Elizabeth Taylor, by allowing the grande dame to push her into a swimming pool, and one about going on a blind date with Sen. Chris Dodd, only to get locked into a tense game of “who could outshock who” with Ted Kennedy.

Shocking isn’t just something Fisher pays a doctor to do to her brain; it’s the pattern of her entire life, and she knows it. Yup, she knows it all, every judgment the reader might make about her — “some eager-to-please (expletive) blathering on about her drug addiction and her mental illness and her poor sad life.” Shockaholic often resembles rehearsal notes for a new performance, and as fun as it is to read, you really want to hear the author tell these stories to you, and to share her laughter. Writing is lonely, and Carrie Fisher wants company. It’s also clear, through all the self-deprecation and self-exposure, that she truly wants to be thought of as “good people,” if only to distinguish her from all the bad people she’s known. She pulls no punches on her stepfather, Harry Karl — “destroying, really destroying something (like, say, your wife’s life), if you want to do it properly, it can take a while” — or on all the ordinary people who make celebrity so radioactive that it in turn destroys the people who are elevated to it.

Unlike Fisher, Keaton (born Diane Hall) is no one-woman show. Smart, insecure and seemingly baffled that anyone would pay attention to her, in Then Again she shares the spotlight with her mother, Dorothy Deanne Keaton, whose surname Diane adopted professionally and whose uncelebrated life story is essential to her own. Then Again is a scrapbook of fragments of Dorothy’s unpublished journals and letters, interlaced with Keaton’s own stories and the archived ephemera of her life. Her relationship with Al Pacino, for instance, is documented in an inventory of “what remains”: “eight pink slips from the Shangri-La Hotel in 1987, saying ‘Call from Al’ ; a letter; a birthday card, and a couple of notes. There’s barely a flicker of scandal: Pacino, Woody Allen and Warren Beatty are all recalled briefly and more or less fondly, with few surprises, though Allen’s fans might care to know that he “had a great body.”