Every once in a while, someone will ask me why my cats always come when I call them. It's because I'm good to them, and they trust me to always look out for their well-being. That includes not hurting their feelings. Yes, just because cats don't show emotion in their faces much doesn't mean they can't be emotionally hurt. You might think, well, they hurt MY feelings when they claw the curtains! You have to remember, cats are animals, and we chose to bring them into our world, so we can't expect them to shed their natural habits and conform to a human way of looking at things. You might not even be aware of the ways you are stressing your cat out and damaging his trust in you.
It all comes down to seeing the world as your cat sees it, and how he sees you. Make his world safe, pleasant, and predictable, and he will thrive and be his sweet, natural self.
(Image credit: Miss Cellania)