From the time they are born, we put our boys in blue beanies and our girls in pink ones. It's a societal norm, an expectation even, that you just are what you are born — a boy or a girl.
From early on, we divide toys and activities by very distinct gender lines, with superheroes and trucks and muck on one side and princesses and dolls and all things frilly on the other.
Many children land, enthusiastically, on the expected side. Others dabble in both "girl" and "boy" things. But what if your kid, even from an early age, mostly showed interest in doing opposite-gender things? More importantly, what if they wanted to BE the opposite gender — or a less-defined mix of both? And what if they wanted to test those limits in public places, like school?