When actor and TV commentator Grodin (It Would Be So Nice if You Weren't Here) asked Shirley MacLaine about her biggest mistake, she suggested he go ask President Bush about his. Others of the 82 celebrity contributors to this collection who look back at lessons learned the hard way squirmed to evade Grodin's truth or dare, while many have risen to the challenge with painful memories of nervousness, humiliation, social embarrassments, shame, regret, denial and guilt. Recalling an incident when she was 13, Mary Steenburgen can still feel my face burn with shame at my own snobbery. After Leonard Nimoy ignored a publisher's warning, fans wrongly interpreted the title of his memoir, I Am Not Spock, to mean he was rejecting the character and all things connected with Star Trek. Walter Cronkite's biggest mistake was retiring too soon. The standout piece is by Pete Hamill, who compresses his entire life into five pages as he reflects on the aftermath of his decision to drop out of high school.