I think it would do great things for the trans community if those who "passed" were more vocal about it. I''m cis, and recently I was at a friend's party and got to know a woman who ended up mentioning that she was trans. I was completely surprised, and it totally changed my perspective on trans people. It's hard as a cis person to NOT have a certain stereotypical perception of trans people when the only time you know someone is trans is when it's blatantly obvious. And as much as I hate to admit it, it's hard to accept that a biological male can actually be a woman when she still externally appears to be male, particularly when you don't personally know any trans people. It's awful, but unfortunately true for a lot of cis people. Once I learned this woman was trans, a light bulb went off in my head. I was like "Oh. Trans women ARE just like any other woman." Realizing that I - a woman - wouldn't have been able to tell the difference, was eye-opening and honestly made me much more sympathetic to the non-passing trans women I encounter. And it made me acknowledge my own internal biases, because I thought to myself, why am I more accepting of someone's womanhood JUST because they appear externally female? The only difference between this woman and the other trans women I see is that she was fortunate enough to have either transitioned earlier in life or been born with a more feminine body. It made me realize that womanhood is clearly not determined by biological sex, otherwise I would have been able to tell this woman was trans!

Of course, no individual is obligated to be some sort of trans activist warrior-type. I totally understand why someone wouldn't want to mention it, and I don't suggest anyone go screaming it from the rooftops or mentioning it to every person you meet - that would probably just be exhausting and borderline obnoxious. But, consider mentioning it to those you feel comfortable around, because you could make some significant changes in how cis people understand trans women.