This is because the other day, I went to fridge two and found none.
Tonight, I had some shaved Parmesan on my dinner. Lovely. After dinner, I looked around for the small plastic box into which I want to put it before it goes into fridge two. (It's a Tupperware "Compact One" with a green lid, for those plastic-box experts among you.) I couldn't find the box. It's the only bit of Tupperware I own with a green lid -- all the others are red -- and I couldn't find it anywhere. In the end, in desparation, I put it in a box the same size and shape but with a red lid. Madness, I know, but there was no alternative. I opened the door of fridge two to put it away, and there on the shelf was the green-lidded box and wouldn't you know it, there was a quarter-pound of Parmesan in it. How did that happen?
A corollary of Segal's law states "A man with one fridge knows where his cheese is: a man with two fridges is never sure."