10YO (in pajamas, 7:50AM): "Totty, I'm not going to school today because I don't feel well."
Me: "You were silly last night and didn't go to sleep until eleven o'clock. Why would you expect to feel well this morning if you didn't get enough sleep last night?"
10YO: "Oh, so I'm not sick?"
...
10YO (in school uniform, 8:05AM): "Bye, Totty!"