Ichi) To echo another, it's worthwhile to note that one can (in the sense of possibility, not of right/s) [in the beginning in particular] believe oneself to be a certain character/person/thing, even if one has no valid claim to the intellectual property. Certainly, believing another to be the genuine character/person/thing is less reasonable.

Ni) There is or was one person in here whose entire past is/was fictional, with only one bridge to reality in the form of a computer game. While he wasn't necessarily sane, he prided himself on his rationality--for the purposes of the entry though, he wouldn't necessarily count, as Ay) the computer game which defined his prior world was without story or plot (specifically: Creatures 3, which deals with artificial life), and Bee) his identity and his past did not originate in any brain other than this.

In any case, I cannot communicate with him at present.