Are You There God? It’s Me, Margaret, the iconic book about puberty and preteen firsts, debuts on the big screen later this month, along with the much anticipated documentary, Judy Blume Forever. Social media has been abuzz with fans spanning generations sharing their own #MargaretMoments.

Here’s mine: When I researched and wrote the book Periods Gone Public: Taking a Stand for Menstrual Equity in 2017, I delved into the national discourse about menstruation in the United States during the 20th century. Of course, Margaret plays a leading role—but so too, I learned, does the invention and commercialization of modern menstrual products.