You are part of the 30% of the population for which the placebo effect works. Other things to notice: how flexy your crank arms are (0.008 inches? WHOA!), and how stiff your wheels are.

At low speeds like this, the effect of rotational inertia is negligible, due mostly to the fact that the chainring and chain don't make up that much mass, and the difference in radius is only 1-2 inches. The one phenomenon I have witnessed, however, is how smoothly and quietly the drivetrain is with a larger rear cog. This is very real, and is the reason I won't run anything smaller than a 17T in the back. Efficiency is increased as well, but only by a teensy bit. For you, this probably amplifies your placebo reaction.

Do note, however, that track racers do like to distinguish between large/large and small/small for different events. We had a discussion about this in the track forums a while back, and the consensus was: tradition. It's all because of tradition. Not that there's anything wrong with that.