Answer:
Turns me on my backs and open up my stomach. You will be the wisest of men though at start a lummox.
Without a bridle, or a saddle, across a thing I ride a-straddle. And those I ride, by help of me, though almost blind, are made to see. What am I?
Before Mt. Everest was discovered what was the highest mountain in the world?
I go up and never come down no matter how hard you wish. As I get higher more wrinkles crawl onto your face.
I am in the past never in the future. I don't exist but have existed. I saw what you saw and that is what I will ever see.
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.