Space Time Continuums
“Rifts in [space time] continuums are one of the handiest inventions of science fiction” ~ Roger Ebert
Not only are they handy in science fiction but I am pretty certian they are handy for explaining lost socks and misplaced keys.

Yep. I’m pretty sure that the Einstein-Rosen Bridge theorem was born when Einstein’s misplaced socks started turning up in Rosen’s clothing dryer.
I don’t know for sure, but I’ll bet that if you slipped into a dirty sock, climbed into a dryer, and programmed your trusty calligraphic robot arm to turn on the dryer once you shut the dryer door, you’d have a 50% chance of falling through a crack in the space-time continuum before the drying cycle were over.
Of course the other 50% chance is that you’d be baked inside your own dirty sock while the dryer went through its cycle and that the calligraphic robot arm would then assume your persona, steal your girlfriend, and make you look like a fool while getting drunk off of motor oil and cheap vodka. But hey, 50% isn’t too shabby, that’s a flip of a coin.