As a child and young adult, I played a lot of Japanese role-playing games (JRPGs). A common feature of the JRPG is the ability to rename playable characters to whatever the player wishes. When I first started playing JRPGs, I fell easily into the tendency of naming the central protagonist after myself. When I was playing such games as a child in the late eighties and early nineties, the games being produced contained almost exclusively young, male protagonists. I also spent the majority of the games controlling the behavior of this character. And so, their was little, if any, cognitive dissonance in giving my name to them and imagining it was me discovering such fantastic worlds instead of them.
In 1994, a game called Final Fantasy 6 was released in the United States (though it was called Final Fantasy 3 at the time; the reasons for that constitute a story too long to tell here). Final Fantasy 6 upset my ingrained naming strategy by introducing me straight away to a female protagonist at the game's onset. At the time, I was a boggled, perhaps even a bit upset. I left her name as it was, and continued playing. Within half an hour of play, another namable character came along, and then another, and another, and another, and soon it was all too evident that none of these were the "main character." In fact, Final Fantasy 6 has a cast of six to eight who are central to the plot with another six or so side characters.
Final Fantasy 6 was the first story that forced me to question identifying myself directly with the protagonist, though I'll admit I still had a lot of work to do in that regard throughout my adolescence.
Perhaps this was why, by my late teens, when I discovered a science fiction TV show called Farscape, that I became confused by the comments upon the (then nascent) internet fan forums for the show. The two most mind-boggling elements I discovered were the existence of "shippers," fans who yearn for certain characters to form romantic relationships, and also of a general attitude of disdain for something called a "reset button story," a plot construct Farscape utilized at least twice before I gave up on the series in the middle of its third season. The term "reset button" applies to any story in which the events of the story are caused to have never happened as a result of changes to the story's timeline (alternate realities, time travel, etc.).
The "reset button story" of my formative years was the Star Trek: The Next Generation episode "Cause and Effect," in which the ship and its crew are caught in a temporal paradox. They are eventually able to escape the paradox by discovering how to pass information from one loop to the next, helped along by the auditory echoes of previous loops. I enjoyed this story as a child, and I still enjoy it as an adult.
However, a person who dislikes reset buttons would argue that this story and all others of its type are flawed storytelling. When the majority of the episode's events are erased by timeline changes, the argument goes, then "nothing has changed." This is portrayed as a sort of fatal flaw, as though the purpose of a story is to cause change for its characters. I thought the point of a story was to change me.
I remained befuddled by this argument for years after first hearing it. Eventually, I would think back to my childhood experiences with JRPGs and put two and two together. If an observer's goal is merely to identify as (not "with," "as") one of the characters, then a reset button story does the unthinkable: it forces the observer to invest their own ego into their favorite protagonist's struggles, only to wrench all that away at the end and revert the character to their original state, a situation that I'm sure is incredibly frustrating for fans who form such relationships with characters, much as I was frustrated when Final Fantasy 6 presented me with my first naming opportunity and the character and I didn't share the same gender, as every JRPG prior had.
As I suggested above, experienced participants in literary or cinematographic art do not identify as the characters in a work, they identify with them. It comes naturally for the inexperienced reader to pretend that the events of a book are actually happening to them, but a more skilled reader does the mental work of imagining that characters are fully-realized people with many differences from themselves. It's quite an effort, but it's incredibly rewarding. Entirely new facets of human existence open up that were inaccessible (because they were unimaginable) before.