Why won't a cow walk downstairs?
OK, imagine you are a cow. Now walking up, most of the weight of
your body is down and back, and your knees bend helping you push
yourself up. Now walking down, most of the weight is on your front
legs, and your knees bend and point down the stairs, and with all
the weight and the very real possibility that you could tumble down
frontwards, you just won't do it.
But, you say, I see cows go down hills all the time in John
Yes, they do down hills, but the sides of the hills are not
broken up by STEPS that cause you to , as it were, go on faith that
the next step is short enough that you won't trip.
Think of it as you woujld a child, kids will first start to
climb UP steps, but getting them to go down takes a lot of patience
and care by the parents, till they learn to walk down.