I think that the built environment greatly supports who you are. If you take your home for example, everyone may not have the opportunity to physically build or change the room to how they would like it but that aside everyone is different, tailored to everyone's personality. Even dorm rooms where the majority of them are physically built the same very few if any look the same. Because everyone takes their space a shapes it to show who they are. With the way they layout their furniture and the type of furniture, what colors they paint the walls, what type of pictures or posters they display, their personal belongings in their home and how its organized or disorganized are all a reflection of "who" someone is.
If you've never seen two of your friend's homes and you went to each of them without knowing who's place you were going to I can guarantee that you would be able to tell who's room is who's just with the way they have them "reflecting" "who" they are.
I think this is one big reason why when so many people have the opportunity to either build a house or buy a house they choose to build because I think most people prefer to live in a place that could "reflect" them in every way possible because that is where the individual feels most comfortable.
If i were to switch homes with a friend for a period of time; I would probably begin to feel displaced after a while. I think this is similar with animals in a zoo. You cannot just put an animal in like a 10x10 stall and expect them to live like the would in the wild. If you look at zoos the majority of them have shaped the animals living spaces to simulate their natural habitat's and because of this a lot of animals have survived better in captivity, even though no matter how good you make the zoo it will never be like the wild.