I’ve slept on hardwood floors and couches (not the same) and rugs without issue. Granted the floor ones were all one night events where I was hammered, so idk. I just know when I don’t use a pillow I wake up with immense back pain so suck it nerd
I sleep in either briefs, sweatshorts, or sweatpants depending on the season. And either nothing up top, a t-shirt, or a light sweatshirt.