I suppose I am what Renee would call 'over imaginative'. I had an invisible friend when I was 6.
According to my parents, me and my brother had invisible friends when we were under 6. We called them "Hansey" and "Poco". At some point (and I have no memory of this, just going by what my parents say) me and my bro got mad at our invisible friends, stuck them both in a mailbox, and sent them away forever.
Perhaps this was my first action of "dead is dead". Lol.
Over half a century later, I still do. Lol. As you know, I tend to RP from the perspective of traveling with my character as a companion or mentor or 'invisible friend' to my character. We chat constantly while playing, although the other NPCs can't hear me, for I am inside my character's head. Sounds like you are familiar with that concept, as well as the idea that many RP'ers use of 'becoming' their characater. Hmm. . . a couple things that I believe help me:
Similar to me, although my character can't truely hear me, though.
I start my character with sort of a bare-bones backstory (rather than something pages long full of extreme detail) and then I get to know my characters over time. He or she reveals their past thru inspirational moments and insights. In my opinion, my characters are
not just in my mind; they actually exist. Not as pixels on a TV screen, but as essences of energy. :chaos: