I once read that you can never have all the planes in the world on the ground at the same time because there isn't enough space in airports for them all. This means you have to have some in the air at any given time.
I don't know if this aeroplane fact is true, but finding myself in a rare moment yesterday of having washed and dried and folded all the clothes in the house I realised I was doing myself a disservice. I can't fit them all in the drawers and wardrobes. It's actually better that there are a few half-dirty piles of clothes somewhere (too clean for washing machine, too grubby for wardrobe), and a 'waiting to be ironed' pile (a long wait). And in a 'convenient place in case we need it' pile. And in a 'at the bottom of the stairs waiting to be taken upstairs' pile. And so on.
It's no good getting all the clothes nice and clean and folded, some clothes need to be in circulation at any given time because there's no room for them all to be stored.
And I've noticed it's the same with mugs. I need one in my hand with coffee in it, and at least one used mug in each room. Otherwise if they're all clean and dry they don't fit in the cupboard. The same goes for toys, children's artwork, random and important bits of paper with numbers on and just about everything.
There's either too much stuff which needs to be stored or not enough storage for the stuff. One or the other. And this is why our house is untidy. It's full of stuff in circulation. And this is the excuse I have ready and waiting for husband when he gets back from a week away this evening. It's not me being untidy, it's just the House's Stuff and Storage Mismatch. A known and recognised scientific state.