I get reminded of it fairly often, even though I'm read as male constantly, and stealth to the majority of people that I spent my life around. There's only a few people that I see every 6 months or so for 3 week periods that know any other, as well as my girlfriend.
As I'm pre-everything I get reminded most times that I speak, as although my voice is clearly acceptable enough not to have had people question me on it, I can hear the difference myself. I can also feel my binder, especially towards the end of the day, or if it wrinkles up, which is a pretty sure reminder that not all is how it should be. Then there's me having to consciously remind myself that I need to walk past the urinals and sit to pee as well, which always grates. Looking like I'm fifteen rather than eighteen is also an issue for me, as I can't go and buy alcohol/cigarettes/or even come across new people at work without being questioned severely on my age. Minor things like not being able to buy adult clothes that fit me is also a reminder sometimes, although I'm getting over my hang ups about that now that I've found Primark sell XSs which are actually XS, and some places which sell kids clothes that don't look childish. Even wearing my work PPE, which only goes as small as a small is a bit of a reminder of how small I am though, and why I am that size. Sex is becoming increasingly more of a reminder now too.
Logistics cause a headache for me too still sometimes, the logistics of still having one or two things in another name that I can't bring myself to use when calling up to change it, so it doesn't get changed. The current one, is the logistics of only having access to a shared shower/toilet room which has no locking doors on the shower, and only a window which may as well not be frosted and a curtain to protect me from anyone seeing me naked.
You can still be treated as male as anyone, but still have reminders from your physical self. People very rarely bring it up with me now, just my girlfriend pointing out I need to book my train tickets and get ready for my next appointment, that my favourite binder is dry, or other mundane things that have become so normal in our life that we don't really connect them with me being trans. I'm hoping that one day when my physicality is starting to fit what it should have always been then it will be less on my mind, as it's jarring with me less.