This being in the triathlon section, no one should be surprised that many posters track their numbers, since that's often part of a triathlon training program. My coach also uses Training Peaks, so as I report what I do for each assigned workout, TP amasses that data for me. Good thing, because I find the act of logging stuff kind of boring. As part of training, though, it has a real purpose.
Since January, I've done:
119,560 yards swim
1601 miles bike. But I never enter "trainer miles", so I have no idea what those would add. I have a hard time grasping the idea of "trainer miles". 
295 miles run.
"My predominant feeling is one of gratitude. I have loved and been loved;I have been given much and I have given something in return...Above all, I have been a sentient being, a thinking animal, on this beautiful planet, and that in itself has been an enormous privilege and an adventure." O. Sacks