My own marathon

Yesterday I went out for a long run. And I mean LONG.
You see, I ran 13 miles yesterday, the length of a half marathon. Brian asked me why I did it. That part was obvious; I wanted to see if I could. I think that has been my whole push to run that distance. Just to see if I could do it.
It takes me a really long time to run 13 miles. Way too much time to think about what I'm doing and why.
So when I got home, I was an interesting mix of happy and sad at the same time. I was happy. I mean, I ran 13 miles! I have been saying that this is the longest distance that I will ever run in my life. It's my own marathon. Sad because I realized that getting there was all the fun. I have no desire to repeat that feat in a race now. Maybe ever.
My knees are tired. I know all about muscle soreness but this is joint soreness. There is no pain but there is definite soreness. Now, if you examine my motivation to run for the last 2-1/2 years, you'll note that it has been all about health. That's why I'm jogging races instead of run-walking them, right? To be exact, it's about my health when I'm 70 or 80. I want to be doing things right now that will make me at the top of my game then. I realized yesterday that the feeling in my knees is most likely not going to be good for me when I'm 80.
I read somewhere a quote from a doctor that said if anyone is running more than a 3 mile run, they're doing it for reasons other than health. I think that he means the wearing parts of running overcome the cardio, muscular and skeletal benefits of running at around 3 miles. I think that I agree with him. Maybe the distance varies a little from person to person but I don't think you can exceed 10k distance without doing it for a different purpose.
So am I going to run longer distances than 3 miles? You betcha. Because I don't think that it is causing damage (or else I would have some kind of recovery times) for me to run 10ks. But I don't think that I'll go longer than that. I can work on my 10k time for the next 10 years and be perfectly happy. Besides, an hour out of my day for a race or training? That's something that I can live with for the next 50 years of my life.