Why is hotel check-in at four o'clock

My flight landed at eight in the morning. I have been awake for twenty-two hours. I am standing in a hotel lobby holding a coffee I do not want, and the gentleman at the desk is explaining, with real sympathy, that check-in is at four.

Checkout is at eleven. That leaves five hours in which, I am told, the room is cleaned. I have seen these rooms cleaned. It takes forty minutes and a cart. I understand that the hotel has a schedule, but I also understand that there are three hundred rooms and that surely one of them is ready.

I will be in the lobby. I will be in the lobby for a long time. I have taken the good chair by the window and I will not be giving it back.