Yeah, no, you are wrong. We are social animals. We haven't evolved to be happy alone. My wife is my best friend. I am absolutely the most happy when my best friend is around and the least happy when she is away. I love doing things with her, talking with her, etc. I have tons of hobbies and interests that don't involve her. I could easily fill my days with those things. But frankly they aren't on the same level as my wife in terms of generating happiness, not by a long shot. And I don't think it is co-dependence. It's just best friends enjoying being together.