I'm never going to understand how you're supposed to do that trick where you tie a knot on a cherry stem with your tongue. I've only seen it done in manga. I'm thinking it has to be a Japanese urban legend.
No, it's a real trick. There are articles and YT videos if you want to try it. Apparently some guy managed to tie 14 knots a minute for Guiness record. Sounds whacky fast, but ok.