I don't know about your house, but in ours, some things seem to multiply until we have such an abundance that it seems to be all we can do swim our way through them. While other things: well, they just disappear. It doesn't matter how many we buy, we just can't keep them in our house. Here's an example:
At the moment, with some of our family away on trips, and visitors here ... we have a total of 4 people using this particular bathroom. I took a picture of just the one end ... note: 6 toothbrushes. The other end has a sonic toothbrush with 3 heads and one more regular toothbrush. That makes a total of 10 toothbrushes (and that's just what's on the counter). 4 people. No one will claim any of the regular toothbrushes. How does this happen? They're like bunnies ... they multiply when I'm not looking.
On the other hand: it looks like we have a plethora of socks ... be it known that not a single one of these has a mate. I promise: I bought these in pairs ~ I did NOT buy them as single items! It's gotten so bad that my girls actually started a new trend this year at school ... it's now the cool thing to wear mis-matched socks. It's about time someone started that fad.
I could probably figure out the mystery of the missing socks if I worked at it hard enough ... but the multiplying toothbrushes??? I haven't a clue.