I've had this experience repeatedly over the last few months - I wake up about an hour or so after falling asleep, and I'm convinced I'm alone in a strange room (or an abandoned shop, or a tent, or a filthy B&B etc etc) with no access to a loo, and I haven't taken my nightly medication.
It takes me a minute or so to reorientate myself, and I realise I'm at home in my bed, DH asleep beside me, the loo is across the landing and of course I've taken my tablets, as I have every night for 20 years.
It's a really odd, disturbing sensation and it feels like it's every night.
Does anyone else get it, what is it? Alzheimer's is rife in the family so I'm understandably worried it's a sign of something!