My back would be killing me if I sat on the floor like that!
Not if you learn to sit right, although floors take some practice. It takes very little practice, though, to realize that hard-surfaced chairs are much more restful/restorative/relaxing for the spine than soft, cushy ones. :yes:
Any time I feel tired or sore, or have to sit for a long time, I look for the hardest chair around, and specifically keep a couple of un-padded wooden stools in my apartment, just for de-compressing and relaxing my spine. It is a little hard on the 'sitz-bones' sometimes if you sit for too long (several hours or more will leave two tiny round bruises there), but the rest of the spine, and the whole body (limbs as well) will become relaxed, loose and rested-feeling, even light and transparent, as if you had had a good massage and a few hours of sleep, if you sit correctly on a hard surface for long enough. It is almost impossible, except with years of dedicated effort and training, and perhaps not even then, to get that effect in a soft, cushiony chair.
It's another one of those perverse and counter-intuitive realities/truths that people find weird and hard to accept at first, but I GUARANTEE it is TRUE. You just have to learn/know HOW to sit, to learn this for yourself.