having chosen mud and dirt trial I've found out I'm pretty mainstream but why gravel wasn't among the options ?
I'd say mud and bare feet are a match made in heaven, but dirt trails, sand and good old grass are decent substitutes. I guess my soles simply like whatever soft stuff nature provides!
There's just no winning roads and paths of dry dirt, made warm by the mid-summer sun. Mud, while pleasant, has the problem of sticking to your feet, which forces you to take time to scrub it off before you get back inside, because I certainly like my floors clean. Also, tree bark. Snow is very unique, but unfortunately laws of physics make sustained exposure impossible to maintain, unless you really enjoy damaging your body.
IMHO, to see the sun rise and set walking on a warm wet beach is the best, from March to November I always drive barefoot and a dusty trail isn't foreign to me at all...carpet,tile, warm blacktop, wet grass, they make me enjoy the summers more and appreciate the changing seasons too....
I live in a place covered by pine trees, it took quite a while before getting accustomed to them. where they are really a threat is on the pavement... i've witnessed motorists fall over them and skid away on the asphalt and i myself a couple of times almost met the same fate :\
All I got here is beach pavement and sidewalks without taking a ride someplace. Still want to goto Arcadia national park to go barefoot hiking .
I think that is the best conclusion. Soft dirt and soil feels good, like you are eating cake Warm blacktop is a warmer, like having hot soup Rough gravel is like chilli