I had a friend in high school who got squeamish at the sight of blood, or at least that’s what we all thought. She went on to become a surgeon. Turns out, it’s the idea of people being in pain that got to her. Operating on someone who’s out cold was absolutely fine even if they’re gushing blood all over the place, because they can’t feel it.
My one dog is very special. She likes to sleep with her head under the couch. She was not pleased when we got a new couch that her head wouldn’t fit under. She sometimes runs into walls and falls off of sidewalks.
My other dog is entirely disinterested in toys. She does not play with them, ever.