I was trying to get a 3 prong plug into a 2 prong receptacle when I was about 14-15, ok maybe i was 16. I need some a/c !! anyway, after that I swore up and down that the white wire was always The hot. we had the 4 circuit edison based fuse panel.(thank GOD no-one jerry rigged them with a penny) I knocked out my moms coffee pot, couple of lamps and maybe even the washer machine.
277v in an emergency lighting fixture, where on is switched and one is always hot. It was supposed to turned off as my Journeyman assured me. Never trust your Journeyman when you are green!
he laughed for long time . It hurts

I did not get as think so badly as you shocked I did.