Tim and I have noticed that the ground has been getting harder and harder. Once a thin mat was adequate for camping. Our sons could sleep on anything. As the years went by we bought thicker, more high-tech camping pads. Then came the big step to an actual air mattress, one of those thick bed-like ones, but it was cold to sleep on. Now when we camp, we sleep on the thick air mattress with a wool rug on top, and are seriously thinking of bringing along a memory-foam pad.
Our resting place on our recent trip was a very nicely appointed condominium - worlds apart from camping. The condo had an enormous and very comfy mattress, the kind that cradles one's joints, not too soft, not too hard - ahhh... just right. As much as I love sleeping with only a layer of nylon between me and all outdoors, on a cold and showery late October night I appreciated a mattress that was - just right.