Re: Windows 10, it scared me so much the first time after a bigger update with the "Hi / We've updated your computer" type splash screen. "FUCK did it just reformat everything??"
"Hi, we've updated your computer. Pray we do not update it any further."
I also experienced that moment of "oh shit!". I've rarely used Windows in my life, but when I have, when Windows blanks the display and pops up something like that and isn't booting, it's historically something scary.