As soon as we start to stumble along on our own we take a look at the people, things, and events around us and adopt some of it as our own. This is me. I'm four or five. Maybe Christmas has just come because I have a toy six-gun and a cowboy hat. Oh, and a doll. The doll is a 'boy' doll in that it was dressed in pants. Already showing my preferences by picking toys, huh? I'm sure I begged for the gun and the hat. The doll was meant to try to interest me in dolls, I think.
We grow up with this set of cultural things associated with our parents' beliefs about religion and life. We see what girls are supposed to do and want. We desire things we see touted to us, by society or marketers. No one is immune. But from a very young age, we may pick and choose and question. We may accept some things only to reason out a rejection later in life. I recently rejected football and years of being caught up in the vast cultural sinkhole that football is in our culture. And. I don't own guns either!