Had a little chuckle about the “hotel pillows have eaten more retainers than you’d think” bit—can confirm, I once found mine wedged behind a nightstand two days after I thought it was gone for good. Still cringe remembering that panic.
I’m with you on the bottled water. Maybe it’s cautious, but after a trip to Morocco where the tap water made my stomach do somersaults, I just stopped taking chances. Even rinsing my retainer with it left me uneasy—probably in my head, but I’d rather not risk it. I usually buy a couple of big bottles and set one aside just for dental stuff.
I also keep a ziplock bag in my toiletry kit to stash the retainer case if it’s still damp or if I’m in a rush. It’s not fancy, but at least it keeps things from getting gross. And honestly, the backup case is smart—I had one crack in my suitcase once and I was stuck using a plastic cup for three days. Wouldn’t recommend.