My catfriend seems reasonably happy but he was raised by humans.
The backstory that we know is that his mother was hit by a car before his eyes opened and he and his siblings were bottle-raised by a retired recent widow with no children. Her rescue kittens are what she does. Locally, they are so well known that many people think a "Hername Kitten" is a breed.
Catfriend is very social and compassionate. He can be sleeping across the house from you and somehow sense when you're sad and need a cat. Technically he isn't even my property, but when my kid was allowed to adopt him, it was with the understanding that Gramma was going to be his regular sitter and legal guardian if the college-aged kid couldn't take care of him.
Mostly he seems happy but the college-aged kid is busy and doesn't have much time for him. I can't let him into my bedroom any more because he knocks over my houseplants. Sometimes he just gets lost in the shuffle and than he understandably acts out, attacks the plants out of anger rather than hunger, etc.
He has a few rules that aren't flexible, such as the litter box MUST be changed twice a week, but mostly he's pretty laid back. He's just a bit confused and neurotic because he was abducted by aliens as an infant and raised by humans.
That's certainly understandable.