1. one has been alone too long and has developed voices in their head, :P im getting there. there by talking to the voices because they thin they are real.
2. next hell i do it when im mad. >.< when ever things dont work the way i thought they would i get mad and talk to myself. my old man does it. :o at least 10 times a day!!
3. they have that multiple personality think in their head and argue with whom controls the body when
4. if you so lonely you have several THOUSAND pets and talk to them. i do it with the three dogs here when im alone.
5. i guess satan or god could play a role in people talking to themsevles. sure why not add that to the list.
6. ok this takes the cake, when a wiken,,wi..>.< f-word i cant spell it, but when a demon summoning goes wrong and the summoner is possesed or stalked by the spirt of the paper imp or a pocket pixie

if anyone see's ive missed one please add it in a comment and this strictly comical not ment to pick on anyone. and yes i do have a twisted since of humor. ;) thanks for reading