Regrets, who doesn’t have them? Who hasn’t made mistakes? Relationships, jobs, passions, living locations. Sometimes we took too long to end them or change them. Sometimes we jumped too early. Sometimes we never jumped at all and are now trapped in some hellish half-life. ...

These questions are of special interest to psychologists and philosophers, who reflect on life’s choices, on its possibilities and constraints. Each in their own way try to construct an adequate model of free will and determinism, of agency and structure, of identity and personal change – of who we are, of what makes us, of what we can do and what we can’t, and why this is so. 

Science fiction has its own privileged sub-genre for examining these questions, one particularly suited to thought experiments about personal timelines, decisions and their consequences, of who we are and how we became that person and not someone else, another version of ourselves – the time travel story.