Hit 1,200 board feet of trim last month and it stopped feeling like a job

Last month I ran 1,200 board feet of poplar trim through my miter saw on a trim package out in Franklin, and somewhere around foot 900 I stopped counting cuts and just started feeling the rhythm. For 6 days straight it was crown, base, casing, repeat, and my back hated me but my hands knew what to do without me thinking. I used to chase every cut with a pencil and a square like a nervous rookie, now I just trust the saw and check it after. The number itself did not matter, but the fact that my body knew the work before my brain did told me something clicked. Any of you ever hit a point where the reps turned into instinct, and when did you finally notice it?