Fatigue: you know you're tired when you're on the trainer looking for an easier gear and there isn't one. Then you check to see if your son has cranked up the flywheel stiffness and he hasn't.
Pre race fitness and weight for a nonsprinter: you know you're there/almost there when a set of hollow cheeks greet you in the mirror and your colleagues at work keep asking after your health. And you know you're NOT there when the same people tell you how well you look (ie round cheeks).
Lack of understanding: how do I convey the enormity of the task I've set myself to my non racing friends?.... You're going to ride for an hour????!!!..what's so hard about that?
"Race face": has everyone got a load of pursuit and/or TT photos that all look exactly the same..same expression on the face...your "race face"? I have. The way I can tell them apart is from the helmet ..from thin plastic shell to Louis Garneau to Specialized to Bell to LAS..or the bike..from 650C wheel little beauty to Colnago and the skin suit..plain, to Eastern Vets, to Blackburn CC to Victoria to Australia and now to my new sponsors Spoke(n).