Try for a goal that's reasonable, then gradually raise it.

If you want to run, run a mile. If you want to experience a different life, run a marathon.

A runner must run with dreams in his heart.

An athlete cannot run with money in his pockets. He must run with hope in his heart and dreams in his head.

By a persistent effort of will it is possible to change the whole body. The athlete must always keep in mind this concept of change and progression. He must never accept his limitations as being permanent, because they are not.

I was not talented enough to run and smile at the same time

If you come to think of it, you never see deer, dogs and rabbits worrying about their menus and yet they run much faster than humans.