500th test on the same unit? My buddy had to do that for a whole certification cycle once. He said he started dreaming in G1000 menu trees. He'd wake up trying to press the "CLR" button on his alarm clock. The man could navigate the terrain page blindfolded by the end of it.
Yeah, that deep muscle memory is real. I knew a guy who could do the whole startup sequence by feel alone, like typing without looking at the keyboard. It got to the point where the actual plane felt like an extension of his body.