I saw a meme, "My genitals do not define my gender."
If your genitals do define your gender, then if you lose your penis in an accident or are born without one due to penile agenesis, you are not a man. This is not how society sees such men.
Essentially, society is very happy to classify penisless men as men, unless they are trans men, in which case some people get all exercised about genitals defining you.
As for trying to fit in, that is pretty much what almost every trans person is trying to do.
I'm pretty sure my chromosomes define my genitals and my genitals define the way in which I sex someone up. Chromosomes also define the way in which my brain is orientated--male, female, or anything in between. Society defines our gender, and being an anti-social personality type, I've never really cared much for what society has to say about anything.
There are some social rules I am forced to follow, like don't shoot cops at random. But other than that, as far as I am concerned, penises are for fun, copulation, and secretion ... not labeling. I'm straight because I use my penis exclusively on women, and I am a male because that is how my brain functions structurally. I'm a man because I say so. No backing from society required
