It’s important to realize your mistakes and learn from them, says writer and actor Charles Grodin. So he asked more than 80 celebrities and other notable folks to describe their biggest boo-boos in life and the lessons they gained.

What’s in it for the reader? Well, not a lot of profound insight. The advice given in “If I Only Knew Then … Learning From Our Mistakes” (Springboard, $24.99) is pretty garden variety – seven contributors produce some variation of, “Trust your gut instincts.”

Thank people you appreciate before they die, says actress Barbara Feldon. Appreciate what you have, says Goldie Hawn in reflecting on her last day at the TV show “Laugh-In.” Don’t let emotion overrule reason, concludes journalist Jonathan Alter.

It’s hard to draw a widely applicable lesson from some of the other contributions. Walter Cronkite laments that he retired from the CBS anchorman’s chair too soon, for example. Sen. Orrin Hatch regrets voting against the establishment of Martin Luther King Day. Not really situations most of us face, and if there’s some larger lesson from their mistakes, they don’t help us understand it.

But that hints at the most interesting part of this book: the glimpses into the lives of famous or noteworthy people. We learn that even as a TV star, Carol Burnett became disastrously tongue-tied when she met Cary Grant. Peter Falk talks about his experiences with a glass eye. Ben Stiller wishes he had stayed in college.

Stuff like that keeps many a magazine going. And it’s the real payoff here.