It's usually embedded in our memory banks for the rest of our lives -- the circumstances and emotions surrounding the first time we had a period.
Perhaps we felt timid, scared or embarrassed. We were certain that we were different, in some crucial and perhaps life-threatening way, from
everyone else. Maybe we told our best friend, but maybe we didn't. We felt awkward about all the "now you're a woman" overtures in the health movie we saw at school, and even more awkward dealing with the products (and the cramps, ugh!) that were so unfamiliar. And boys seemed, more than ever, like an alien species.
Later in life it's a story we freely trade with our girlfriends, laughingly and knowingly, because it's such a shared experience. In fact, a thread on Empowher about first periods got quite a bit of response:
https://www.empowher.com/community/share/my-period-story-whats-yours
That's exactly the kind of thing that author Rachel Kauder Nalebuff set out to capture in “My Little Red Book.” It's just a small book of 92 collected women's stories about their first period and the circumstances around it. The entries are each a few paragraphs long, and they come from women of all ages and locations.
A funny paragraph excerpt from the NYTimes Health story about the book:
"The author Patricia Marx was furious at her first period, having decided by age 15 that she was going to be lucky enough to skip the whole thing. Cecily von Ziegesar, author of the “Gossip Girl” series, was one of untold thousands to be flummoxed by a box of applicator-free O.B. tampons. The runner Kathrine Switzer had to prime the pump with calories: only after she gained 15 pounds with peanut butter and chocolate milk did she begin to menstruate."
Here's the full story:
http://www.nytimes.com/2009/02/24/health/views/24book.html?_r=1&ref=health
The author's on a book tour now; I can only imagine the comments and stories she's getting from her book-readings and signing audiences!