This is the same thing I notice with working out or learning anything, the start is the worst part because the goal looks stupid big and you feel dumb for even trying. Fifty bucks every two weeks sounds like nothing when you say it out loud, like why bother, but that is kind of the trick. Small stuff you can actually keep doing beats big moves you quit after a month. And the app showing a number going up is its own thing, it messes with your head in a good way because you start to trust yourself. Then one day it is just there and you are standing at a bus stop like wait what.

Wait, your old boss taught you to cut flush and you just never questioned it for 9 years? That blows my mind because I feel like even the basics of pruning say leave the collar. I get it tho, if that's how you learned you just keep doing it without thinking. The part that gets me is the homeowner catching it in the moment and actually showing you the dead bark, that had to sting a little. At least now you know and your cuts are healing up right.