why would they?

They think of you as either their best friend or their best feeder.

I once caught my cat sleeping in my neighbours ground level bay window, his reaction was just like he was my wife and I walked in on him sleeping with tyrone.

If you had a pet for 5 years, and someone took it and started feeding it, sheltering it, etc would the pet literally forget who you ever were?

>>2112651
I left on vacation with my family for 10 days and had to leave my cat with a friend whose pretty good with cats. She said he just hid the whole time, never saw him eat or anything while she was around. When I finally got back he was the clingiest cat ever, rubbing all over me, not letting me go two steps without tripping me if I didn't pick him up, etc. So yeah I think they've a concept of who we are pretty well

Going by a interpretation of ownership that is different from what others have touched on, all of the dogs and cats I had in my life are certainly possessive of specific toys, bowls, sleeping places, and cushions

>>2112650

Cats seem to have a concept of separate relationships and families. We used to have a cat in our court that was old, and frail and pathetic and my neighbor and I would both feed him. He would go over to their door and beg and act pitiful and then get full and happy and then wait for them to go away and then come over to our door and do the same thing. If they stayed outside or came back out he would abort pretend like he wasn't getting fed again.

Left for three years and when I came back my cat was so clingy and affectionate, spent the whole evening purring and slept next to me. Not sure what that means but I figure it means cats, at least, develop strong bonds.