Some of the worst norms start out this way, don't they >_________>.
Thank you though! I guess the question is, why has it stuck for so long, especially when most wouldn't know of the history behind grass... 
@thecrystalrook
Yes. I never went through this phase when I was a kid, but I only think that's owed to my odd circumstances. Had I been exposed to society earlier, I likely would have been a "Not like other girls" kid, too. I still had a version of it, which was more broad. "I'm not like other people". 
From what I've observed, the behavior is one that's guaranteed to happen because of how much 1) society hates teenagers, and especially girls. Literally everything girls do is "annoying" or "girl drama" or "childish", but when a boy does it, it can be charming or funny (This is not to say boys "have it easier". Both genders have it insanely hard in very different ways), and then 2) how much society values "being unique". They want special stand-out people. They want everyone to be creative enough to still be within their confining box but at the border between acceptable and way-too-out-there. So society tells everyone, "Be unique, because being normal is boring!", then mocks girls for trying.