I love running.
I love it because of how clear a metaphor it is for so many aspects of life. It's one of the simplest ways to teach yourself how to become a better person. For example, the experience of pushing yourself after you think you have nothing left is something you can transfer in your work or relationships.
Running has taught me a lot about myself, including the fact that I am capable of more than I previously thought. Just when I thought I couldn't run any longer, I somehow found a way to keep going. (mostly with the help of running with other people)
It turns out that whenever I feel like stopping, I usually have more than a few miles left in me. Thinking that I couldn't keep going was all in my head. I had a self imposed limitation that wasn't reflective of reality. The cool thing is that the more you push yourself the more you realize that you don't know where your own limit is.
If this is true for running, where else is it true? That is an exciting question to wonder about.