This is what keeps me going. It makes me go harder, longer and further than ever before. A few weeks ago, I went for a morning run. It was the longest run I have ever done. I went 4 miles. For some that is nothing, it's a walk in the park, but for me it was an accomplishment.
I kept saying it to myself. Although, I was a little more harsh about it. In my head, I said, "Go until your body gives out, then MAKE it give you more." I believe that you have to push your limits to succeed. If all you ever do, is what you've done before, then how are you ever going to become more than what you are?
So, challenge yourself. See how far you can go, before you turn around and go back. If it's not hard, then it's not a challenge.
Just some motivation to curl up with.