03/20/2012 04:35 pm ET Updated Mar 20, 2012

Anne Lamott And Sam Lamott: The Moment I Knew I Was Really A Parent (VIDEO)

While some parenting books offer preachy "mean girl" advice, Anne Lamott's "Operating Instructions" has become a shining example of a memoir about motherhood that tells the scary but comforting truth. Before there were mommy blogs, Anne filled that need for moms to know they weren't alone in their doubt, fear, joy ... "I’m probably just as good a mother as the next repressed, obsessive-compulsive paranoiac," she wrote.

Today, Anne has a new memoir on sale, which was co-written with her son, the baby we first met in "Operating." In the book, Sam -- who was only 19 years old when his own kid was born -- grapples with many of the same experiences his mom faced raising him. Simultaneously, Anne learns new lessons about what it means to be a grandma.

When the Lamotts visited the HuffPost offices to share those learnings, both mother and son joined the ranks of contributors in our exciting new project, "The Moment I Knew". In her clip (above), Anne tells us about the feeling that let her know she was a really a parent. And below, Sam recalls one very specific experience that told him the same.

Watch both here and then, submit your answer to the question...