My 40th birthday hit me harder than I expected, and not for the reason you think
I turned 40 last month and was fine with it, but then I realized I've been flossing the same two back molars for 15 years. That means I've said 'open wide' to roughly 8,000 patients since I started, and I still can't remember which side has the crown without looking. The number that got me wasn't 40, it was 8,000, because that's a whole lot of times I almost dropped a mirror down someone's throat. Has anyone else had a random work-related count suddenly make them feel ancient in a weird way?
Did you ever count the chairs you've had to raise or lower over the years? I've been assisting in a dental office for 12 years and one day I added up the total hours I've spent holding that suction tube. Sounds dumb but it messed with my head for a week. The trick is to stop doing math on stuff you can't change. Pick one thing you're actually good at now that you were not good at 8,000 patients ago and write it down somewhere you'll see it. For me it was getting faster at setup and knowing what the dentist needs before she asks. That count means you've had reps, and reps are how you got good.