I wear a mouth guard at night so when I clench and grind my teeth, they don't get so damaged. Years ago now, like maybe when I was in my 20s, and still living at my parents house, I'd just gotten a night guard from the dentist. Pretty early into getting it, one night, I put it in my mouth and went to sleep. In the morning, it was not in my mouth. I figured it fell out but I never found it. I will never know if I went sleep walking and threw it out, if I swallowed it (which would have been really hard to do with this one), or what.