Heartbreaking doesn't cover it. Devastating, demoralizing, crippling. Even these words don't describe what a DNF does to the runner. You're right about quitting though. I've run through many injuries, even a cracked femur, but the first time I DNF's because I was unwilling to run through the pain of a torn ankle, I was crushed. I was crushed because I didn't finish. I was crushed because I had given up. I was crushed because I didn't have the mental strength to run through the pain, there were only 3 kilometers to go! I was crushed because I knew I would win my age group in this race, because I had beaten everyone the week before. At 19 years old I ran my last race.
Flash forward 10 years. My job is getting stressful, I'm not eating like I should, and my knees ache every time the weather changes, so I decide to start running again. For a year I take short, slow runs, and my knees feel better, I feel better. I start to race again, and I love it. I can't believe I ever quit. I look for a new challenge at every opportunity and I become a runner again! I complete 3 marathons, I race Around the Bay, I start to climb to the top of my age group again, and I DNF. I had started the race with a cough. "Nothing to it." I tell myself. I can still run, and I don't feel too congested. My friends and family tell me I'm nuts, "You aren't well, just sit this one out." I've been called nuts before, heck, most of them tell me I'm nuts to run that far when I'm well. Only this time they're right. Your body doesn't work right when it's fighting off a virus. Your muscles don't get the oxygen they need when your lungs are full of fluid (it did end up being pneumonia). I quit. I seriously contemplated sticking to the short races. No more marathons, no Boston time, I don't need this.
Thanks Sandy. Thanks for reminding me that quitting one race does not mean the end of racing. Thanks for reminding me that I've been here before. Thanks for encouraging me to move on, recover, and get 'em next year! That nut is still there, I just need to be patient.

Mike