It Smells Like Home

You know when you get the sort of strange feeling when you step into a friends house for the first time. You don't know where anything is, you're not quite sure how to go about doing anything, and the entire house smells weird. Not necessarily a bad smell. although that can happen, but it's as if you're surrounded by something your body has to get used to. It can take some time.
Eventually, as you become better friends and you visit their house more and more often; you'll start the notice the smell less and less. It will become second nature for you to be in this house. You may not even remember that it used to smell so different to you, now you don't notice any difference from anywhere else in your life. Why is that?

I know when people come to my house for the first time I have asked what they smell that's different than what they're used to. They mention that they can tell I have a dog. Does it smell bad like a dog? No, simply that there is an animal in the house. (Although I do live on a farm which likely adds to the animal tones in the air as well)

Friends have also mentioned that they smell cookies and/or whatever baked goods when they're in my house. My Mom and I love to bake so this is to be expected. I like that what people can smell in our house has a lot to do with who we are as a family. 

I don't notice these smells anymore as it is my house and they are perfectly natural for my brain to register. So why would my brain bother to alert me of a smell I am completely surrounded by at most times? We would go crazy if we were constantly bombarded with every smell we ever came in contact with. Our brains adapt to what smells are part of our usual environment and adapt our processing of these smells to be basically under the radar.