lost items, parallel universes, and Douglas Adams
.. as in the 'lost biro planet' from HGG:
Somewhere in the cosmos, he said, along with all the planets inhabited by humanoids, reptiloids, fishoids, walking treeoids and superintelligent shades of the colour blue, there was also a planet entirely given over to biro life forms. And it was to this planet that unattended biros would make their way, slipping away quietly through wormholes in space to a world where they knew they could enjoy a uniquely biroid lifestyle, responding to highly biro-oriented stimuli, and generally leading the biro equivalent of the good life.