Sorry I am late in congratulating you, but as a 3 years plus non smoker myself, I find I don't even think about smoking at all, or checking this site.
Congratulations and best wishes. Although I can't run marathons due to knee problems, I do like to swim and have found that I swim better and breathe better, and of course all those other things you mention that are better as a non smoker.
I remember my last cigarette too, out on my balcony. I had saved some old cigarettes, that were stale, and deliberately smoked those near the end so that smoking would not be enjoyable. It was nasty, and I smoked it to the end, and that was it, I was done. I had started prepping myself several weeks before, with mental verses "Success is the only option, failure is not an option." I repeated them over and over, especially the first 72 hours. I had lots of thoughts of going to 7-11 "just for one pack" the first couple of weeks. (I did not go, and we know it probably would not have been "just one pack." Luckily, I found this site when I was looking for a Recovery from Smoking timetable, and found the articles very helpful. I read Joel's entire library twice. My favorites include "Tearing down the Wall (of nicotime dependency)."
Yes, we are very lucky we made it, and will continue to be smoke free, forever, as long as we NTAP.
AnitaMCK - Free and Healing for Three Years, Four Months, Eighteen Days, 10 Hours and 12 Minutes, while extending my life expectancy 64 Days and 9 Hours, by avoiding the use of 18546 nicotine delivery devices that would have cost me $3,904.30.