The other night as I was watching TV on the couch, I saw that he returned to exactly the same cat he was before his accident. Just flipped right over and laid on his back to watch TV upside down. And he just laid there happy as a clam and continued to do so for at least an hour. Of course I had to take some pictures - and of the pictures I took, very few were actually back to back, he was just calm and happy, but silly.
Hope you enjoy the video!