Back after I graduated high school, and while living with my parents, I was given a sort of tacit permission to smoke in my bedroom. Kind of a “we know you do it but it’s not really causing an issue so we can’t say much.” There were two windows on perpendicular walls, so if I cracked them there was decent airflow and the smoke wouldn’t reach the rest of the house. Both my parents smoked, but kept it to the garage
I moved out, and came to visit my mom while she was fixing up the house to sell. She took me up to my old bedroom where she was painting the ceiling. She was halfway done. One half was white as snow, but the other half was a nasty, drippy-looking, phlgemy yellow. It took her three coats of paint to cover it.
My first apartment on my own I smoked in. It was a dump when I moved in, and the landlord was planning on a refurbishment after I moved out, so he didn’t mind. As long as I didn’t punch holes in the walls.
Now that my girlfriend and I own our house, we don’t smoke inside. It just makes things gross, eventually.
When you’re younger, it’s easy to forget-or not realize-the cost of owning a house and that smoking inside, while it’s a choice you get to make if you own the place, can degrade things and be a cost down the road if you ever have to sell.