Alittle over 5 years ago a stray came through my cat door. I found a rescue that adopted out cats through Petco, and I fostered him. Compared to my 14 lb. Sugar Ray, he seemed so tiny, but he was actually eating pretty well--he had been someone's kitty, I had made an appointment to have "her" spayed and then the vet told me he was a male that had been neutered already.
Anyway, I was told he was probably about 4 years old. Last September the rescue called me and said that the individual that had adopted him 5 years before was having to bring him back---her husband had developed severe allergies and had given her an "ultimatum". I thought OK no one is going to adopt a black 9 year old cat--and I couldn't let him be taken to a shelter, so after talking to her & realizing that she was so upset I had her return him to me. He is mine now

We laughed because she said when they moved the year before she had taken him to a new vet and she told the vet that he was a rescue and she wondered how old the vet thought he was, since she really didn't know. He said about
5 years old.
Truthfully, after getting him back, I think he probably is now just about 6. He must have been alittle over a year when he first came here--or I assume the vet would have been able to tell that he was under 1 year.
But seeing him now, I am convinced that he was a young cat back then. Pictures I have of him then, show he was just not a really mature cat. He feels--can't see as he has long hair--very thin now and he weighs 12 lbs. as opposed to 7 lbs. back then (when he also felt thin, but not emaciated)....his hair has really grown much longer, his face just looks bigger, too. It is just so hard to tell.