Closets

Unlike most old houses, my house--at least upstairs--has closets. It also has built-in wardrobes in two bedrooms. One bedroom is even lucky enough to have a closet and a built-in wardrobe.

But the weird thing is that my bedroom doesn't have an original closet. Or, at least, not one that I've been able to find evidence of. Instead, I get a whopping huge built-in wardrobe and nothing else.

So why doesn't my bedroom have a closet if the other three do?

My bedroom is part of the 'addition', somewhere between 1912 and 1920. And that would make sense if my office was also closetless, but the POs combined the closet from the bedroom that adjoins my office to make a secret passageway closet that joins both rooms.

In between my bedroom and my office is the upstairs bathroom, but as far as we can tell, it's the original bathroom to the house. (Or, at least to that part of the house; there was an outhouse too.) Since I'm assuming that all three rooms were added at the same time (that makes sense, after all) then it doesn't make sense to think that the bathroom--or a portion of it--was once my room's closet.

Any suggestions as to why my bedroom wouldn't have a closet?