It definitely gave me pause - I learned something similar from my dying grandfather, who I thought was becoming uncontactable. Then one day, taken into the hospital and given IV, he really came to and became mostly coherent again. We had a great few hours with him and some of his friends who were there to visit. (He died a month later, and it is long ago now.)

Just think of, how much temporary conditions shape how we see people.

(And yet more horrifying, there are cases of comatose people coming to temporarily, being just like themselves, only to never wake up again.)