We adopted Carsi when he was eight months old. As far as we know, he was left behind by his owner as she moved and he was taken care of by nice people but lived on the streets. When we adopted him, he was in the Vet's office being treated for pneumonia. It took him several weeks to get closer to us but he did. Now, after more than one and a half years, he comes to my lap once or twice everyday. However, whenever we stand up and start walking in the house, we observe that he is really scared and starts taking shelter under the couch or table. We feel disappointed that he still does not feel at home and threatened by us even though we speak very softly to him and act very affectionately. Do you have any suggestions for us so we can have a relaxed and happy cat?
You should be patient and understanding. Some cats have very easily broken heart. I am speaking figuratively, of course. Some events leave deep steps in their souls, shock can be never forgotten, that affects the behaviour. Cats can't talk, they don't have therapists who could help them to overcome their problems.
I guess, that betrayal of his first owner, living in the street (=being almost homeless), illness and a lot of manipulations that vet did with him to cure - all these left step in his personality. Taking shelter under the table or sofa is kind of unconscious response.
You shouldn't be upset. This is him. Sometimes even old former homeless cats become domestic and tender very quickly. Sometimes, once betrayed pets can never become "normal".
I would recommend you keep trying to "protect" him. If your house is big, buy him a special cat's house, small place, where he could feel safe and comfortable. Keep touching, talking (yes!) and stroking him. If you are persistent but soft, you'll have success. But be ready that he'll stay fearful. It won't mean that he doesnt love you or feel unsafe or he's unhappy. It just means that the past can't leave him. Only love (he feels it) and patience can help you.
I've been in that situation myself; here's what I found helpful.
First, realise that your cat's behaviour doesn't mean that he doesn't trust you. Clearly he does love and trust you; he shows that by wanting to be in your lap. So when he hides from you when you're standing up and walking around, think of it as an involuntary reflex that has nothing to do with his feelings for you.
Next, try to break the association between your action (standing up and walking around) and his response (hiding). One way to do this is to keep treats handy, and toss one on the floor when you're standing still. Gradually he will learn that good things happen when a human is standing still. Then move on to walking very slowly around the room and tossing treats. Eventually you should be able to walk normally. But make the training process gradual, and if at any point he goes back to hiding, go back to the previous stage for a while.
Another way to break the association is, next time he's on your lap, make a small movement as if you're going to stand up, but stay seated. The goal is to move just enough so that he's alert, but not enough so that he runs off. Over time, make the movement bigger. Eventually you should be able to stand up, and all he does is move off your lap and onto another part of the sofa.
If you don't already have a cat tree, I recommend you get one. It will encourage your cat to spend time high up, which is associated with feelings of confidence, rather than slinking about under things. A nice high one with a shelf where he can be at shoulder level would be ideal. This will allow him to feel less threatened when you're walking around the room. You can try approaching him when he's on the shelf, and offer him a treat or praise.