Asking for my cats.;-)
Even creatures other than man have created their lifestyles, as primitive as they may be. So they are self-aware that their survival depends upon the skills they have to develop. They even are aware of of their similar beings that they grew up with, be it another cat or a dog. It will mourn its loss, but it soon forgets and continues on. It that mate, for lack of a better word, is reintroduced it will be recognized, when they have the opportunity to smell it, provided it hasn't taken on some other scent. 🤣 When one of our dogs, we used to have, went to the groomers it would take some getting to know you time to realize who this dog was. 🤣
One thing they will never question though is how they got here in the first place. 🙂👍