This child walks up hill daily to carry water to his family.  We went down the hill to the stream, and back up.  The incline was incredibly steep and rocky.  On the way down, I was sure I wouldn't be able to make it back up to the top on my own.  I did - but my legs are still aching days later because of it.  When I got to the bottom, I saw an old lady filling up her buckets of water and realized that she does this every day - just to survive.