As a teenager, my mother would step into my bedroom, get one sniff, let me know I needed to fix that (aka clean my room), and leave again. I am sure she would come down to communicate about something much more important. She would get one whiff, forget everything and would get out before the smell could penetrate her. I used to think she had an over sensitive smeller. Now I think, I was equipped with a defense system similar to a skunk. As a parent she presented a danger to my teenage social life and social appearance; in defense my body would use its defense trait to keep any adult far away. How do I know this..... it is hereditary!
That's my theory and I am sticking to it!