It taught me that most bedrooms dont have enough air flow, it helped me figure out just how much i need the window open or not closing the door which improved my sleep. Also helped me see the importance and notice the effect of having a air filter, and fine tune location and fan speed. I find that air quality is something you get used to and dont realize the effect it has on you unless you pay attention and experiment. its not something i pay attention to every day i could probably use it 1 week 2 times a year and have 90% of the benefit. That being said a lot of people probably live in better more well designed places with less issues than i have.