Some people have strange gaps in their knowledge.
I was homeschooled, so when I started ninth grade there were a number of things I didn't know, like Juliet by LMNT* (remember sixth grade?), ten fingers** or the rape song***. Then there's this awesome kick-ass friend of mine who can rattle of a sting of jokes dirtier than your 15 year old brother's browser history, but who I recently discovered didn't know what a brazilian wax is.

So, I think I'm going to make a list of random things everyone should know by the time they're in tenth grade.
Swell.
Let the fun begin.

* Here's the first stanza and the chorus:

Hey I've been watching you
Every little thing you do
Every time I see you pass
In my homeroom class, makes my heart beat fast
I've tried to page you twice
But I see you roll your eyes
Wish I could make it real
But your lips are sealed, that ain't no big deal
'Cause I know you really want me
I hear your friends talk about me
So why you trying to do without me
When you got me
Where you want me

(Hey Juliet)
I think you're fine
You really blow my mind
Maybe someday, you and me can run away
I just want you to know
I wanna be your Romeo
Hey Juliet
 

** Thanks wikipedia:

"Ten Fingers is a party game that begins with all players forming a circle and putting all ten fingers up. The game starts by having a random player saying something that they haven't done, such as "I haven't been to Paris." Anyone who has done the act then puts one of their fingers down. Play continues with the next person in clockwise order who states something that they haven't done until only one player has any fingers remaining. However, unlike traditional games, there are two winners: the player who puts all of their fingers down first and the last player remaining. As this is a party game, questions tend to be raunchy and sexual and therefore favor the most promiscuous or most prude players."

***  Here you go:

 Stop, don't touch me there.
This is my private square.
R-A-P-E
Get your hands off of me.
It's RAPE

Stop, don't touch that place.
This is my private space.
R-A-P-E
Get your penis out of me.
It's RAPE