13
Star Trek transporters
(lemmy.world)
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. The best ones are thoughts that many people can relate to and they find something funny or interesting in regular stuff.
That last part about there being two of you reminds me of The Prestige. I won't go into further detail in case I'd be spoiling it for you, but would encourage you to watch it if you haven't.