There's probably a word for it in Japanese
◊ I want to know if there's a word for the feeling of coveting something you already have.
It's not "satisfaction." It's closer to "greed." It's about holding something you own and being awash in a thick, syrupy joy that you own this thing and it is all yours and you are the only one, or one of only a very few, who owns anything like it.
It's possibly the best feeling in the world.