[novok]

I knew of an old thai man who's face looked like he was 80 and his body looked cut and jacked. He also preferred to sleep with a thin mat on a hard tile floor with his wife in a house where there were multiple clean, usable beds to easily sleep on instead.

So if your body adjusts to it, it's definitely possible to actually prefer it.

[Terry_Roll]

Hard perfectly flat sleeping surfaces with just a simple blanket for warmth can stimulate the lymphatic system much like a massage can.

The worst is when you have an uneven surface, like when camping and there is a rock which even your (inflatable) roll mat cant dampen out, that makes sleep difficult.