[throwway120385]

Actually sleeping on a softer mattress leads to more restful sleep for me. I used to sleep on a firm but my partner tries to get the softest mattress she can and I've found that it works a lot better for me than my old firm mattress did. The moveable bases, when adjusted correctly, also allow me to completely relax when I'm asleep and I rest a lot better under those conditions. I notice the difference now whenever I'm traveling because the hotel beds are usually rock hard. Mattress salespeople actually do know what they're talking about some of the time.

[codethief]

I don't know. Humans have slept on the ground for hundreds of thousands of years and now soft mattresses are supposed to be better? Call me unconvinced.

(FWIW, to counter your personal experience with some of my own anecdotal evidence, I always sleep much better on firm mattresses.)

[jjk166]

Humans suffered colds without antibiotics for hundreds of thousands of years. Just because we can endure certain circumstances does not make them optimal. Our ancestors certainly didn't avoid softer sleeping spots because of some benefit the firmness of the ground provided.

[throwway120385]

Humans didn't sleep directly on the ground. Even in hot environments if the ground is even a little damp it will suck all the heat out of your body and chill you to death. What humans have always done is built an insulating mattress out of whatever material is at-hand and then slept on that. You can sleep on straw, dry grass, dry leaves, sticks, burlap or whatever you can find. But you never just sleep straight on the ground.