Funny you should mention the steepness of the Great Wall; at the time of my first trip there, I was in, oh, pretty good shape; I ran a few miles every other day or so... But I'm telling you: that fetching wall is STEEP!!!!! For about 100 yards I was literally on my hands and knees. The slant was so great, it was totaly impossible to stand on your feet alone. There were very few steps; it was mostly a very sharp slope. The ground was dry, and the weather was clear that day, but if it had been the least bit wet, at a few points I would have lost my traction and slid a quarter of a mile or so down the mountain. I have NO Idea how armored men went up and down that thing...
As I was climbing - not walking, climbing - up the Wall's path, I noticed an old, hunched over, Chinese woman slowly climbing the Wall ahead of me (and carrying a large bag, to boot!). Well, me being a typical man, I thought to myself: "no old lady's gonna beat ME up this mountain!" and I re-exerted my efforts to climb quickly.
As I wrote, I was in pretty good shape back then, and I am also a fairly experienced climber, but I never even came close to catching up with her!! for all the effort I put into it, she stayed the same distance away.
When I finally made it to the top - completely drenched in sweat and out I'd breath - I approached the old woman, who was casually sitting on a small bench by a souvenir vendor (and who, by-the-way, showed NO signs of having exerted herself in the least; the show-off!) and offered her my hand to congratulate her. The vendor spoke English, so I spoke to the woman thru him (I can speak Japanese and Korean fine, but my Chinese wasn't up this level...). I found out tat the woman was his mother, and she carried a bag of water bottles - quite a few - up to the top of the mountain THREE times a day (!)to sell to tourists like me.
I obliged them by purchasing three bottles, I think.