Often times I finish a race and know that I didn't perform at the level I am capable of. Sometimes it's lack of training or temperature during race day ( like Boston this year). Friends, family and workers all say, "wow, you are fast" "3:03 is such a fast marathon time" but it's not your PR or sometimes even close to it. Anyone try explaining to the non runners that even though you ran much faster than they ever will, you aren't happy with your race? Or do you just say thanks?