I've started planning a story based in modern times, and the character who's story I will be writing in first person is loosely based on somebody I know - that is, he has similar characteristics, and a dysfunctional family, though I have exaggerated and changed parts of his personality. My problem is this - when writing drafts for sections of the story, I can't envisage anything but my friend, and therefore start writing as if I am him, not my character. Has anybody else had this problem? Can anybody suggest anything I could do to give my character a sense of identity and to disassociate him from my friend? Thanks a lot.