I remember way back, fresh out of high school, I registered for the Seattle Marathon. I ran that whole summer. In fact, it's pretty much all I did. Or, more rightly, everything I did was around the running. I was the lightest I've ever been in my adult life (to the point where some people became concerned), I was putting in the highest consistent mileage I'd ever done, I was focused. Until I got injured just a few weeks before. I ran it anyway. On pace at the half-way point, I blew up at about 16 miles.
I had done some personal "artwork". Also revolved around running. It included things like pacing for a 2 hour marathon. Inhuman. I remember when Salazar ran 2:08:13 and thinking how incredible it was that he threw in a 4:32 mile late into the race to shake his last rival.