Break Rules 1, 2, 3, 4, and 8 from previous list.
Really, I am hypothesising two causes for the 'average' result last night:
(1) Lack of fluidity in hips, due to not having my usual Monday massage or a chiro visit (felt like a newborn giraffe with my legs about to give out from under me at any moment).
(2) A small virus, elevating my heart rate, which meant that my effort was harder.
Or maybe I just didn't try hard enough.
Anyway, I am consoling myself with the fact that Rolf DNF'd. He's really good at laying down on the grass during track races. He's elevated it to an art form :)