I have 3 laid back boys too and while we knew two of them had had a home, and had no trouble acclimating to the house, one was certainly a little more house-daft. He had not been in the shelter long when we picked him up but we do not know how long he was on the streets. We doubt not long but it was kind of obvious he came from somewhat deprived circumstances.
Teppo was 3 yo old when we got him, and while it was obvious he knew things like couch, TV and fridge - he seemed to be pretty ignorant of lot of fun things a cat could do. I literally taught him to play. I showed him where he can go but every time he'd be walking around and an item was in a new location (say shopping bag on the floor) his butt would drop, and he'd approach it with great caution. He still has some of that behavior with odder/darker items - when his brothers hurry to sniff feeling secure in home environment. And he's the least scaredy cat in general! Unfortunately, he also was very unfamiliar with car while he otherwise is the least bothered by loud noises, thunder etc.
I think the oddest thing was the playing to me. He really wanted to when he realized what was going on but was quite lost and clumsy. Now he is the toy hog, getting back all that lost time. He learns all new things slower than others though, and I think it is because he has not been exposed to lot in his younger years. He sure knows human food and telly, so I think I know what he has been doing!
