>>521057After years of back trouble, I threw a 4x8 sheet of 3/4" plywood onto my bed and covered it with a 4x8 sheet of 3/4" blue board foam insulation. I have a couple thin blankets over that. It is essentially hard as ground with a sleeping bag. Everyone else hates it. I've been sleeping on that for 3 years now and haven't had back trouble since.
Sleeping on the ground isn't even a thing for me. Hell, a normally carpeted floor feels too soft for me now.