Why do I talk to myself?

I sometimes have debates or I have interviews where I pretend to be someone of another race or gender in my head...I say it out loud like when Im doing tasks. I dont want people to hear so when they walk in I go silent but I fidget because I want to finish the "interview" or "debate"...sometimes people answer in my head but its seldom when they do...I usually answer questions I know are said in my head but werent actually said...confusing I know but its what I do. Whats wrong with me?