Humans are ergonomically designed for walking. I'm travelling, and have little opportunity for walking right now, and boy, what a mess I become. Walking - and for me, that means being outside - clears my head and puts me in touch with reality. The weather, the phases of the moon, the time of day, where I am, what's happening in the neighborhood, how's everybody doing, greetings to the cats and dogs, listening to the birds and frogs and bees and cicadas or whatever's about, what's in bloom, what's not. Meaning, walking keeps me sane, and not walking, I'm just a notch above insane....