What we're really getting at now is the idea of roles, as explored in this LW post from last year. (The comments on that one are fantastic.)

Developing personas to play in different contexts -- and training to swap between them -- is, I think, incredibly valuable. The persona I developed for my day job as a teacher is actually quite different from my default personality, and has its own contingent sub-personas that I shift into as circumstances warrant.

"Time traveller", "clone", "fork" are, in this sense, useful meta-roles that may help give your other roles additional purpose and focus.