Apple Mac wireless mice are fun...
As they're bluetooth and can connect to two laptops at the same time. This can occasionally cause some confusion...
I've also got a friend who swears by a long list of magical/religious concepts, drawn from a melange of occasionally contradictory sources; crystal-energy, reiki, dragons, demons, ghosts, telepathic messages, curses, tarot cards, scrying, etc, etc, etc.
In fact, they swear that many of these things have a measurable physical impact, but oddly, any time there's an opportunity to check this, there's some obtuse reason why they can't be tested[*]
It's especially strange since they're usually flat-broke and James Randi still has a 1 million dollar reward outstanding for anyone who can produce evidence of ESP and telepathy, crystal energies and Reiki would all seem to fall very firmly in that category...
[*] Or, as happens with increasingly annoying frequency "Oh, you don't understand because you're a muggle". I didn't particularly like Harry Potter *before* people started using that term as a put-down...