...the cats know it.
Zorg went out of town for a couple days, and the cats immediately shifted into one-owner formation. Betaille came inside for the night and slept on (rather than under) the bed. Zoe, who usually yowls annoyingly at 6 a.m to remind Zorg that it's time to get up and let her out, didn't say a word, and waited for me to get up at 8.
I love the way the cats learn to shift back and forth between different "modes." Sheba can tell the difference between weekends and weekdays. A few months back her calendar got off, and after I ate breakfast she waited, with obvious impatience, at the door of my office under the impression we were about to start our usual "workday" together — with her snoozing behind the computer and me typing away in front of it.