I don't know how everyone else lives their lives but, personally, I never have a reason to think about the genitals of about 99.9% of the people I meet.
If you say I'm a she/her or a he/him I take your word for it.
If you say I am a they /them that's all good too.
If your pronoun changes and you let me know that's a-okay, I might still get it wrong sometimes but I will do my best.
This obsession some people seem to have about the contents of other people's undies is really disturbing.