I had a roommate who could decently understand japanese this way. We had him look away and translate for us a few times and he was spot on. I’m sure if he put effort into speaking it he could have learned to do that as well.

Used ophcrack back when I was a teen so i could learn my parent’s windows password and fuck around when they were asleep. Then I figured just using live cds was cleaner (no browsing history to delete). Then once they upgraded, I was given the old pc to nuke and pave as I saw fit. It was a lot of fun outsmarting my parents in the wee hours of the night, not that they were terribly tech savvy.