I don’t know when or how it started but I became convienced as a kid that some demon or satan himself lived literally underground and might come up through the toilet when I was most inconvienent so I always did my buisness right quick.
As a rational adult though of course I no longer believe that’s going to happen- instead I’ve seen videos of toilet spiders hiding in wait and news stories of snakes coming up for a bite… I’m still quick to shit.