The old tech in Reno who made me redo a whole panel just to show me one wire
Last spring I was doing a panel swap on a little shop off Wells Ave in Reno and this older installer named Ray was watching me work. He pointed at my ground bar and said "run that one again, you got it under the lug but not all the way in." I pulled it, redid it, and he made me do the whole row over so I'd feel the difference with my own fingers. Cost me 40 minutes and I was annoyed at the time, but now I check every lug that same way. What's the one thing an older tech made you redo that you still do today?