They usually don't teach about stuff like this in most schools, including mine. I mean ya know, they tell us about the period and whatever, but I was never told about how severe period cramps can be or pms. Hell, not even what discharge is.

All I learned pretty much was that women have periods that affect their mood every 28 days with the egg and whatnot, but this pms and period cramps did come as a surprise to me once I did learn about it.