I was running the other night when, after about an hour, suddenly I felt so good, so incredibly good, that I found myself nearly shouting, out loud, to the empty dark around me, "I HAVE NEVER FELT THIS GOOD IN MY ENTIRE LIFE! THIS IS AMAZING!" And then, because I, in the words of one friend, "can't turn it off," I paused for just a moment before adding, still shouting, "I DON'T KNOW WHY THE EXISTENCE OF A RUNNER'S HIGH HAS BEEN SO HOTLY DEBATED IN THE SCIENTIFIC COMMUNITY. THIS IS CLEARLY CHEMICAL. WHEEEEE!"
It's probably a good thing, come to think of it, that I was running alone at night: in the dark, no one can see you make an endorphin-fueled fool of yourself.