Being a night worker I can't say I have a normal 'time to go to bed'. But, there are times I get so sleepy that I start rambling incoherent/silly phrases in a myriad of voices, as if I were angry, distressed, giddy, or whiny.
I should video-tape it sometime.
Here's a good example of something I might say. It just came to me, which must mean I'm starting to get tired.
"The weenies will do whatever it takes!.... POPCOOOOOOORN!!"