Fucking filthy.

While tapestries could help in some small way to cut down on drafts, castle life was usually pretty gross. Instead of carpets, rushes were kept on the floors. On a good day, you would probably find dog shit, food, trash, mice, and any kind of debris in the rushes. Rushes were usually changed but a few times in a year, when everything would be swept out and fresh rushes laid down.

While blowing your nose, tossing chicken bones over your shoulder, and other distasteful dining habits eventually evolved into more refined manners (see Norbert Elias, The Civilizing Process), for centuries, life in your usual castle would have been pretty damn grimy.