Actor, author and CBS News commentator Charles Grodin brings a bit of an edge to everything that he does.

He’s an activist, a former talk show host and the author of five books, including his latest, “If I Only Knew Then: Learning From Our Mistakes.”

Charles says this latest book pulls together stories from 82 people, including himself, who shared their stories of missteps and mistakes. He says producing the book was a whole lot harder than just writing his own book, but he was happy to do it because all of the book’s proceeds go to Help USA, an organization that helps America’s homeless.

He says the topic of the book was inspired by Help USA’s annual fund-raiser, during which the recipients of the aid get up and explain what mistakes led them to homelessness.

So, Charles thought it’d be interesting to find out what mistakes successful people made and what they learned from them. So, called upon some famous friends like Lily Tomlin, Regis Philbin and Gov. Mario Cuomo to tell their stories to help others.

He says about 85 percent of the stories are very serious and, in some cases, heartbreaking, but the book also includes its fair share of hilarious stories, such as the one submitted by Carol Burnett about the time she met Cary Grant.