GIRLS ONLY, NO BOYS ALLOWED

Saw this on Youtube today.  Disney's The Story Of Menstruation.  There were a few comments that said something along the lines of, "I remember seeing stuff like this in school, they had a special class for girls and they'd show us this video/a video like this, the boys would go somewhere else."

There are a few reasons this video annoyed me.  First, the description calling this a banned cartoon.  This was never a banned cartoon.  I hate watching old cartoons on Youtube and just about every one is "banned," or claimed to be.  People just spread misinformation about cartoons being banned, because calling it banned generates more hits (or they just assume that any given cartoon must have been banned, because OMG LADY PARTS IN AN EDUCATIONAL CARTOON?  NOOOOOO!!)  Another reason it annoyed me is that the way the lady narrating pronounces "maturing" is so weird.  Mahtooooring.  The hell.

But the main reason I am annoyed at it is because of those comments, about how girls would have to watch it and the boys would be sent out.  Which isn't directly annoyance at the cartoon, more annoyance at how stuff like that has been educated.  Why can't boys learn how menstruation works, too?  I know most of that sort of stuff happened in Ye Olden Days Of Sexism, but I've heard of it happening in Ye Modern "Post-Sexism" Days* too.  I've met so many guys who have absolutely no knowledge of what menstruation is or why/how it happens.  Once somebody expressed amazement that women get cramps during their period.  Or that menstrual cycles affect hormones and shit even when we aren't bleeding, or that periods may not always be predictable and regular, or that being on your period doesn't automatically make you a RAGING BITCH RAAAAAAAR.  Dudes.  You are thinking PMS.  It stands for premenstrual syndrome.  As in, it happens BEFORE your period, and ends when your period starts.  So if you claim that any lady who acts irritable when you're being a douche "must be on the rag!" then you sound like a complete idiot.  Also, PMS isn't just "ladies hulk out!"  There are a lot of symptoms (and it's not universal either, there are plenty of women who don't get PMS at all) and they can include breast tenderness, clumsiness, headache, and any of these other symptoms here.
*Post-sexism: not actually a thing.

So why can't guys sit in on this video too?  It's not some big secret that ladies sometimes bleed from the crotchal area.  Most women do.  Most guys realize that most women do.  It's pretty hard to get through life without learning this little fact.  So why don't people want to teach boys as well as girls how and why it happens, and what to expect?  There's nothing wrong with learning about stuff that doesn't directly affect you.  And it's a good thing to learn about stuff that directly affects half the people you interact with.  Also, it helps you not look like a fucking moron when I mention a basic fact of life and you are utterly confused because "Durr, what does your period have to do with stomach cramps?"

And for the record, when I give you a death glare and/or punch you for making a PMS joke, it's not proof that I've got PMS.  It's proof that you've successfully pissed me off, because PMS jokes are one of my pet peeves.  How come every time a woman is annoyed or angry it's proof that she's somehow suffering from PMS, even while she's menstruating or has just finished a period?  What, men can get pissed off for the sake of being pissed off but whenever a woman is pissed it's because of hormones?  Fuck you.