It was bloody tough. Walking up 900m in a few hours, walking down steps in the rain, puffing and sweating and plodding. But, I kept going. I kept going up, not looking at the top. I kept taking the next step down, looking for the drier rock, the concavity in the ledge that suggests you're less likely to slip. I told my muscles that one more step could not possibly be too hard. I chatted. I chewed coca toffee. I refused to look over the edge. I listened to my novel. I bonded with my walking sticks. I wore my purple plastic rain poncho with my sunhat. I saw the tiny flowers and the mountaintops. I stood in temples and houses and saw fountains that still run. I ate three course meals and slept in tents that someone else carried. And, after 4 days, I looked down into Machu Picchu and decided to climb another mountain.
Is wasn't as hard as I expected. I kept going, and that's all that was required.