It sounds like we could be twins!

I have always incorporated fictional characters into my imagination and tweaked them to suit the stories/world that I make up for them. I think about the characters constantly, so I tend to become very emotionally attached to them and I like to think of them as imaginary friends.
The only problem I've run into with my love for fictional characters is that I eventually get bored with them and have to find new characters to obsess over. When I was younger, the transition between different sets of characters was rather smooth, but it's a lot harder now that I'm an adult. As of this writing I've gone at least a year (possibly 2) without a character obsession, and it's been driving me crazy!
Well, what characters have you obsessed over before? And I completely agree. I, however, often find new characters to obsess over before the old interest dies out and there's always my failsafe characters that I could never get completely bored with.