I know that feeling too well. Usually it starts with looking down and saying CRAP !!!! In this particular case, me and an older fellow that is a very experienced mountaineer (Logan, Peru, many big peaks) had our eyes on a striking 13er. We tried to avoid the 2500 ft scree slog and ended up on a very slow going 5 hr ridge traverse that had a large amount of "no fall" zones. Storms brewing did not help to settle the nerves either.