I used to play with my sisters dolls all the time, used to bend them up, twist their arms and heads around and scatter them all over the floor so she would scream when she would come back and see them lol.. I played house too, chased all the girls around with plastic flatware, and i ate tons of play dough cupcakes... When i was a kid, pre-school was kind of gender neutral, but i was raised by a father who made sure that i grew up as boy. A lot of times back then i would get into trouble for "playing too rough" or "being destructive" which simply means "being a boy"...
When i have kids, I am going to make sure that their home life is proper, and not any of this gender fluid stuff.. As for who baby sits my kids, It will have to be someone who is old school.