hehe no, not MPD, I'm a writer, and one who uses first person POV at that, and I switch between views often, so i find it easy for me too switch fluently throughout my personalities, as while i dont have Multiple Personality Disorder, I do easily tend to change from day to day.
for me flowing from one person to the next is easy, one place, I'm UltaFlame, another, someone else, each one with there own histories, personalities, and stuff that I come up with, but all have a few similarities, as, even tho they are different 'mes' I'm still the original, so they all derive from me, and share certain aspects of the true blue me.