Why do I run?

I'm back. . . . Well sort of.  I now have a month of solid running under my belt.   Looking forward to doing some racing again at some point, but for now I am settling for a quality hour run through the streets of Clyde, America.  I did a track workout a few days ago, 4xMile @ 5:17, 5:07, 5:01, 4:57 with a 400 jog between each rep.  Nothing special, but it felt good to push my limits again.