Christian GebhardAnother idea of #ToddlerPhysics:
Entropy...when you buy two or more sets of toys, eventually you will get an evenly spread mixture of all the parts.
So from how I "understood" #quantum physics, kids' toys behave like wave functions. There is a region where you'd expect them to be *most likely* (aka the drawer), but there's a good chance to find them in other parts of the apartment, depending on the distance & even in most distant corners the probability is never completely zero.
The wave function collapses when you are - after stepping on a Lego in the darkness.