This is more a life lesson in general, but whatever. It’s also something pretty close to my own heart, because I see it in reference to women in films and video games.
You don’t know people, just because you met someone like them. People are not monoliths.
Don’t assume that everyone that belongs to a particular class/race/gender/whatever is the same. Not all women are bitches, not all black people are criminals, not all gay men are flamboyant… but those are extreme examples. ‘Guys won’t go see a movie with a woman in the lead role!’ NO. Not all men are sexist. There’s all kinds of tiny assumptions you’ll make, based on your upbringing and social circles and experiences, and most of the time you won’t even realize you’re making them.
Don’t assume that all trans* people are comfortable talking about their gender issues because you met one who was completely open about it. Don’t assume that every feminist is a man-hater because you saw one or two insane rants online. Don’t assume that all people of color don’t mind racist jokes because you have one black friend who says it’s okay.
And stop this shit of saying ‘All {insert type of people here} are…’ Challenge it when you hear it from others, even if they say it about privileged people. Analyze what you say and how you say it and who you say it to, and filter out the stuff that sounds like your own pre-conceived notions.
The only caveat to this is that all bets are off, if you’ re afraid for your mental or physical safety. As an example: women know that not all men are rapists. But women also know that giving every man the benefit of the doubt is dangerous, because it’s not as if rapists wear a sign around their necks and the cost, if they’re wrong, is astronomical. It’s a shitty caveat, but again – you can’t hold people’s survival tactics against them.
And there’s a difference between monolithizing a whole section of the populace because of plain bigotry, and monolithizing them in order to survive in a bigoted environment.