Anyone who lives with a cat knows the rule. The box is the destination. The laundry basket is the destination. The one square of paper you needed is, without question, the destination. Size is a suggestion and the cat is not interested in your suggestions.
If I Fits I Sits has been asked about a lot, which is why it is back. The joke works on its own, but the part that makes it stick is underneath it, because what looks like a cat commandeering your space is usually a cat finding a reason to be near you.
The box is an excuse. You were the point.
People do this too, just with less commitment to the bit. We invent errands that happen to go past someone's house. We take the long way because the long way has company in it. Nobody wants to say I would like to be around you, so we find a box to sit in instead.
It is a good thing to notice in the people who do it for you.
The cat is not being weird. The cat has simply decided where it wants to be.
