Writing Games: Once Upon a Time

A dramatic event, or just a couple years, can make someone
into a completely different person; what was your main character like,
once upon a time?

    There's a very bright, nostalgic connotation to the phrase, "once upon a time." It's a classic statement of beginnings, the opening to a story.
    Today, an editor would probably groan very loudly if they saw the first line of a non-fantasy/non-parody story read "once upon a time." But what if it's not a first line, and it's not the narrator using the phrase? I once read a book where the antagonist talked about who he was before he turned corrupt, and he started by saying, "Once upon a time, I was . . ." The way the character used that particular line to define who he was before the written story started was really dramatic.
    And it sounds like it'd make a really cool writing exercise. Not only is it great for summarizing a drastic change in a character, but it can also point out one of the most important aspects of a character, a trait that affects everything they do. For example:
    "Once upon a time, I believed in true love." This kind of statement, spoken by a character at the starting point of the story, would show a vital point in the character's history (a broken heart, perhaps). In addition, it shows what the character's attitude towards this major topic in life will be like; she may scorn the "happily ever afters" of movies with a romance subplot, and roll her eyes when a friend talks about how wonderful her boyfriend is. And since this statement showcases what she's like at the beginning of the novel, it also shows how this belief of the character is probably going to change, that she'll find herself falling in love throughout the course of the story.
    "Once upon a time, I was just a girl who hunted to provide for my family." This would be something Katniss Everdeen from Suzanne Collins's Hunger Games series would say at the end of the first novel. It shows how this was her normal life at the start--youth, a low stature in society, and that she applied her hunting skills to deer and other animals--but it also sums up how the story has changed all that. Because of the events of the story, Katniss's youth and anonymity in her community no longer exist, and her skills with the bow and arrow have been given other applications. This "once upon a time" statement not only shows what she isn't, but it portrays a vague picture of she eventually becomes.
    "Once upon a time, I wasn't afraid to talk about the things that matter." This is something the main character in one of my own stories would say, at the beginning of the plot. It shows the inner issue he has to overcome (his fear of speaking up about his beliefs), and it also hints that something happened earlier in his life that taught him to keep his mouth shut. In addition to these things, the sentence is also really helpful in summing up the character's mindset. Since certain fears can affect everything a character does (like in this situation), it's pretty important to be consistent in the way the character thinks and behaves. A short statement in the character's own words like this "once upon a time" sentence can be very helpful in getting a good idea of that quickly.
    So what do you think? Does this sound like a fun writing game? What "once upon a time" statements would some of your characters say?