By the time your little group reaches the meeting place your mind is still in turmoil from the night before. One moment Elsa was telling you that she was falling for you, and the next she was threatening to banish you for all eternity. You don't know how to think. The revelation that Elsa feels the same way about you as you do about her makes you elated, like you're floating on air, and then her threat forces you back down to earth. To be honest, you can't blame her. Just hearing about this Hans guy makes you want to scorch his sideburns off, and you haven't even had the displeasure of meeting the guy. You think you know who you are, but without your memories, how can you be certain? Maybe the real you is just as bad as this Hans character.
Which leads your thoughts to the other pressing matter: your memories. Do you really want them back? You don't know what your former life was like. For all you know, you got rid of those memories on purpose because you couldn't bear to live with them. You could just start over here, make a life with Elsa and everyone else in Arendelle. But no, Elsa will never trust you until you prove that you are not like Hans. You know that you are a good person, whatever your memories say, and you need to prove that to Elsa. You care too much about how she thinks about you to let her keep distrusting you.
Suddenly the group stops and you look up to see that you have arrived at the meeting place. To your surprise, the meeting place is nothing more than a circle of stones, moss-covered rocks of all sizes scattered all over the place. You are about to ask what the point is when Kristoff speaks out. "Grand Pabbie!" he shouts. "We need your help!"
At the sound of his shout the stones a rumble ominously for several moments.
Then the stones popped open, revealing each and every one to be a different troll, with the moss acting as their clothing. "Kristoff's back!" they exclaim, running up to the bulky man and showing their affection. Then a particularly large and mossy stone rolls into the center of the clearing, opening to reveal a much older-looking troll, a string of many glowing crystals around his neck.
"What is it my Queen?" he asks, addressing Elsa directly. "I know Kristoff would not have brought you here on such short notice without a good reason."
"This man helped Anna and I when we were attacked by brigands," Elsa replies, gesturing to you. "We want to help him in return. He has lost his memories, and we were hoping that you could get them back for him. Like me he has powers of magic, though he controls fire, not ice." She takes a deep breath before continuing. "Also, due to my duty as Queen, I fear I also must ask for the safety of my people that you inform us when you look into his mind if there is any risk to the people of Arendelle. As exciting as it is to meet someone else like me, I cannot ignore the danger that kind of power poses to my people."
"I will do my best," Pabbie assures her before turning to look at you. "Lost memories are usually simply buried somewhere within your mind," he tells you. "If these memories were removed magically, then I cannot return them without having possession of that memory. However, if trauma or something else has simply blocked these memories from your mind, then I should be able to make them resurface." He waves his hands and sparkling energy appears, shifting between them before settling into his fingertips as he places them on your forehead. Suddenly a rush of images fills your mind and the world around you blurs out of existence, replaced by something else.
...
You remember your childhood. Growing up in a simple home in a kingdom far to the south, a place where the summers are hot and winter's bite is rarely felt. Your small family lived in a simple one-room home, but it was enough. You were happy. Your parents were kind, simple folk, and you lived a nice, simple life in your little village.
From a young age you played with fire in both the literal and figurative senses. You would always take risks, reaching for things you shouldn't and jumping spaces that were too far for you to cross. Sometimes you overcame the odds, sometimes you didn't. Every night by the fire you would put your hand in, watching as the flames played harmlessly over your fingers. The first time your parents noticed you doing this they freaked, pulling you away from the fire and shouting, but when they saw your unharmed hand they were shocked. They quickly determine that you must have been blessed, given a gift from God.
Then you began to create fire as well as play with it. Just small pinpricks of flame at first, then fist-sized orbs. You could spend whole nights staring at the flames in your hand, lost in the light and color. Then one day it went wrong and your powers went out of control, burning your small home, as well as several others nearby, to the ground. Luckily no one was harmed, but what had been you and your parents' secret was now known by the whole village.
Unlike your parents, the villagers determined that your gifts must have been the result of sorcery and the devil, not a gift from God. Despite the fact that many of them were your relatives, they determined to kill you in order to keep God's wrath from descending on the village. You fled, leaving the life you knew behind.
You remember running. You traveled as far from home as possible, teaching yourself to control your powers. Your journeys took you farther and farther north, away from the temperate Mediterranean climate and into the colder, harsher lands beyond. You learned how to use a sword in order to protect yourself without revealing your abilities, and you used it often to fight off those who considered you an easy target. For a short period of time you even hired yourself out as a sellsword, but it didn't last. You were too good, too gentle hearted. The life of a mercenary was not the life for you.
So you continued on your lonely road, making few friends along the way, none of which you ever met again. You read whenever you could, though you kept only one book with you for an extended period, a book of legends that you found while traveling through a French village, with one of the legends including someone with powers much like yours.
You remember being ambushed in the mountains. The men were ragged and desperate, but there were well over a dozen of them, and you were not good enough with a sword to defeat them all. In the end you were forced to resort to using your powers. In the rush of the moment you lost control of your powers, fire engulfing everything. Your clothing burned off, the broadsword that you had used for years melting in your hands and your beloved book disintegrating as white-hot flames surrounded you, killing those stupid enough to come close and frightening away the others. You were forced to steal the clothes of the best dressed of the dead men, probably the leader, as well as his longsword.
Wounded from the battle, you made your way to the nearest city, the kingdom of Arendelle. Up in the mountains you were attacked by wolves. You were able to control your powers this time, keeping them at bay with a large hovering orb of fire as you edged away, only to slip on the edge of the overhang you didn't know you were on. You fell, landing on your head, and then... And that is when you reached the point you had just been living.
But this didn't explain everything. What was a videogame? What was a fireman? Why were there a few memories mixed in that didn't make sense, like a memory of eating a meal at some kind of outdoor tavern while people you don't recognize sat around you, all of you dressed in strange clothes? What were these... extra memories? Where did they come from?
...
"(Y/N) is safe," Pabbie declares with a smile. "He is a good man with a true heart, and you have no need to fear him. He has had a difficult past, but nothing that you cannot understand yourselves. I have returned what memories I can. Anything else will have to return naturally, on its own time." He turns to Elsa, giving her a wink. "And I think you should know that he feels the same way about you as you do about him."
Elsa's face goes beet red as everyone else cheers, including the congregation of trolls. Despite her obvious embarrassment, you can see in her eyes how happy she is that her worries were for nothing. Seeing that look in her eyes, you feel like you really could make a life here, with her. However, looking at Pabbie, you can see a trace of worry in his face. He saw the extra bits of strange memories as well. You have your memory back, and you know yourself to be who you are. But that does not mean this mystery is solved. Not by a longshot.
...
Back in the hotel room at the Disneyland hotel, a startling truth is about to be revealed. "You mean you don't remember?" Elsa asks quietly. "Oh (Y/N), I am so sorry. I don't want to have to be the one to tell you this. It still hurts." Tears well up in her eyes. "I don't want to make you have to relive that memory (Y/N), but..."
"But what? What is it?" You are afraid of what she could be talking about, of what terrible thing happened that you can't remember, but you feel the need to know. You need to know what happened to you in this strange and wonderful other life that you are just now starting to remember. "What happened?"
"(Y/N)," Elsa answers hesitantly. "You died."