1. Women stare at your breasts a lot. A study that used an eye-tracking device showed that guys spent more time staring at your breasts, but women also spent plenty of time watching your breasts and not your face. So, eyes up here, literally everyone.
2. Seriously, you're probably wearing the wrong bra size. We've all heard this a million times, but an estimated 8 out of 10 of women are wearing the totally wrong size, so there's a pretty solid chance your breast-holder isn't really working for you. Seriously, just think about how many times you've had a hunch that your breasts were a mystery size and you didn't know what it was.
3. Your nipples can give you orgasms. I know a lot of women feel like this isn't a thing, but when your nipples are stimulated, your brain releases oxytocin, which causes your vagina to contract, which can, uh, obviously lead you to orgasms because that is what vaginas do when things get awesome.
4. There are four different types of nipples. I know that sounds oddly specific but that's only because it is. Are yours normal, flat, puffy, or inverted? Why not grab a bottle of wine and the makings for a Sunday picnic, and spend the day figuring that out! I mean, honestly, what else are you doing on a Sunday?
5. Your breasts are more prone to dry skin than any other body part. Your breasts stretched when you hit puberty, so they have thinner skin than the rest of your body, making them more likely to get dry than other places. And yes, even your nipples need a moisturizer. See? You're already learning so much about your tits. It's a great day.
6. Six percent of people have an extra nipple. Six freaking percent. That means all those jokes on Friends about Chandler's third nipple probably resonated a little too much with a good chunk of the population.
7. Your breast size changes all the time. You can go up as much as a cup size (holy shit!) at certain points in your period cycle, which can be a good thing or a bad thing, depending on whether or not you love wearing button-down shirts.
8. There are over 4 million new bras produced every day. Who is using this much boob armor?!
9. Guys who prefer bigger breasts are less financially secure. According to this 2013 study, guys who hands-down prefer big breasts are more likely to be poor and associate large breasts with large resources. OK, weirdos.
10. Breasts can weigh up to 20 pounds. The average bra is built to support breasts that weigh anywhere from half a pound to freaking 20 pounds, which gives new meaning to calling them "melons."
11. Sleeping facedown can change the shape of your breasts over time. This doctor said it's best to put a pillow under your breasts for support every night. Good night, breasts!
This article originally appeared on Cosmopolitan.com. Minor edits have been made by the Cosmo.ph editors.