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Is cave exploration an indoor or an outdoor activity?
(infosec.pub)
A "Showerthought" is a simple term used to describe the thoughts that pop into your head while you're doing everyday things like taking a shower, driving, or just daydreaming. A showerthought should offer a unique perspective on an ordinary part of life.
Pedantically speaking, I have never been in a door. I've opened doors and passed beyond the portal they were blocking, but I have never phased into or been sealed inside of a door. :p