I'm surprised precisely every time I get my period.
Despite it arriving roughly once a month for the last 15 years, it's always a shock. But when it comes - usually staining a perfectly good pair of undies - there's something oddly... comforting about it.
It reminds me of the weird and wonderful inner workings of the human body, ticking away silently as I'm going about my day-to-day life. How does it know it's been about a month since my last period? How does it know how much blood to let out?
It's very clever, that's how.
So it's time we celebrated it, with all the facts you (probably) didn't know:
1. On average, people who menstruate will menstruate for TEN YEARS of their lives. TEN. YEARS.
No wonder women tend to live longer than men. We bloody deserve it.
With girls typically beginning their period between 10 and 18, and continuing to menstruate until somewhere between 45 and 55, women have an average of around 500 periods in their lifetime.
If the average length of a period is seven days, that's 3500 days of bleeding - almost 10 years.
Considering you're going to spend a decade of your life on your period, it's worth looking into issues that make it particularly uncomfortable - like severe period pain. A visit to the GP can help determine whether it's normal, or whether there are further tests that can look into problems like endometriosis.
2. Menstrual products have an environmental toll.
This one's pretty depressing.
Over our lifetimes, people who menstruate will use somewhere between 5000 and 14,000 pads and tampons. That's a huge toll on the environment.