If I load a camera at home, technically I also then make a new record in the film rolls database on my computer which tells me what it is, what camera it is in and when I started it. So technically I should be able to tell what, if anything, is in any particular camera at any particular point.
In practice, if I forget what it is in a camera I can guarantee that I've not made a database record for it either. I can also guarantee that it will be about halfway through and that I'll have entirely forgotten when and where I took the first half of the roll - let alone why. And I can further guarantee that whatever film is in there will be exactly the wrong one anyway - colour when I just want to take pictures of black and white murals, or 100 film when it's so dim you have to turn the lights on in the daytime.
So I try not to leave film loaded in cameras, except for whatever I am using as a pocket camera, where I don't want to have to think too much.
eta: currently only one loaded I think, an Olympus XA with... er... some 100 film anyway, I dunno.