I think if you had imaginary friends as a child then it's a clear indication that you might be a writer. I did and in truth I liked them and the imaginary worlds I made up a good deal more than real life. I think as a child your imagination can be a safe haven, a place where people are kind and you can process the things in your world that don't seem quite right. Looking back I think that the ability to submerge myself like that protected me from a lot of unpleasant experiences.
I enjoy the company of my characters from my WIP and I spend a good proportion of my commute home from work imagining conversations they might have and how they might make discoveries which help them unlock the case. I consider their reactions and the affect situations might have on them in the short and long term
One of my favourite things about the Beta process was when I got the feedback around how much my betas enjoyed the dialogue and the interactions between the characters. It made me feel comfortable that I had got it right and that they were whole fully believable people.
In between finishing my first book and during the editing process I would imagine what my characters would be doing whilst I wasn't in a position to start book 2 in the series. I wondered if they would be working on cold cases and if they would think that was interesting or dull or frustrating.
I think we all have relationships with the people we create even the villains. Bringing them to life and telling their story is fulfilling. And I've created people that I would want on my side or to share a beer with and I'm glad they're with me on this journey.