It is not true that in order to live one has to believe in one's own existence. There is no necessity to that.
In books and movies, it’s rare to know the entire history of a character before the actual plot begins. In fact, in many books and movies, the only backstory you ever get occurs in flashbacks, after you’re familiar with the character on a more pedestrian level.
The DayTrippers campaign is fine with that. It’s all well and good to expect the Players to create the important aspects of their own characters’ pasts, but it’s entirely another thing to put them on the spot, forcing them to marry themselves to a character concept they haven’t even spent any time playing yet.[continued]