(I don't know how to make this a sticky, but would sure love to have all you add to it and keep it handy)
Some thoughts that have helped me through today:
"Everyone is an athlete. The only difference is that some of us are training and some are not."
--George Sheehan, MD
"Obstacles are those things you see when you take your eyes off the goal."
--Hannah Moore
"Nothing will come of nothing. Dare mighty things."
--William Shakespeare
"There is no failure in running, or in life, as long as you keep moving. It is not about speed or gold medals. It is about refusing to be stopped."
--Ambry Burfoot
"If you want to win something, run 100 meters. If you want to experience something, run a marathon."
--Emil Zatopek