Why is hill running a perfect life metaphor?
Life has its ups and downs. Same as the running. And when everyone wants to make life comfortable and pleasant, we are fast to forget that the struggle and the hardship have its values too.
Downhill running is easy and fast. But only for some time. Then your knees start hurting, you got bored, and you wish for the change.
Going uphill is different. It's hard for the muscles and heavy for the lungs. Your heart pumps the blood frantically, and your vision slowly shrinks. But you carry on, regardless, because you know that on the top you will feel great! The harder, the longer the struggle, more rewarding experience and the bigger sense of achievement. Don't be afraid mountains, run them!