Originally from the kinkmeme, where somebody asked for a fic based on the fact that Levi is a Jewish name. I couldn't help but try and fill.

Notes explaining some of the content appear at the end.

To this day, Levi doesn't understand why nobody else seems to remember what the world had been like before. Some people have books, carefully hidden. Some people tell stories (mostly wrong). But the memories are gone, as if wiped away. There is little-to-naught left of culture, and Levi thinks people feel the lack, but don't even know what it is they're missing. Everybody around him seems to be floating in misery without context, life without past, no hope for a future. If anybody bothered to ask Levi, he could tell them about two thousand years of human history, all learned at his grandfather's knee. He could tell them that there had been great wars before, and terrible cataclysms. He could say that just because they don't know about any other survivors doesn't mean they aren't there - the world is a big place, more vast than anybody who grew up within three walls could ever fathom.

Of course, nobody asks, because nobody knows to.

Early on, he had realized that his family was Different. They didn't like their neighbors, and the neighbors didn't like them. Their foods were different, and they spoke a different language among themselves. None of the other kids knew why this was. Had they asked Levi, he could have told them that it had always been that way, according to his grandfather. Nobody ever liked them.
But what the kids really wanted was to fight, so Levi fought. He was smallest, so he fought the hardest (it had always been that way; the weak against the mighty, his grandfather said, when he came home with a bloody nose for the Nth time that week). He fought more viciously than anybody else, and after a while, he started winning.

His parents seemed undecided about their family history. Often, his father would denounce it all as superstitious nonsense. Why poison the boy's mind? he would shout. Why does he have to bear this weight, when nobody else remembers?But at the end of every week his mother would light three candles and they would all sit and read from those selfsame stories, and Levi learned about the command to remember the days of the world.

He learns hundreds of commands, and when he complains to his mother that it's impossible to remember them all, much less keep them, and what's the point anyway – she smiles sadly and tells him to do his best. We've always survived, she says. If you don't remember, who will? It's not a choice. It's a responsibility.
Levi thinks the rest of humanity is made of morons. Since nobody else seems to remember the point of living anymore, he does his best, and wakes up every morning and says thank you for not making me one of them.

At fifteen, he has his own gang. They combat poverty by redistributing wealth, and Levi makes sure a good portion of it reaches his own family. His father tells him not to steal. Levi retorts that they're not the same as us, so what does it matter? The disappointed look on his father's face makes him wilt, and for a short time after that he confines his activities to bothering the other gangs. It's enough to keep him busy for awhile.

Perhaps his father nurtures some resentment because Levi understands their people's teachings better than his father ever did. He picks up a third language like it's nothing, and is fascinated by the intricacies of several-hundred-year-old legal arguments. He understands that the laws of a king aren't necessarily the laws of morality, and that every phrase can be interpreted a hundred ways. With this understanding, he looks down on the primitive judicial system and finds the simple laws easy to circumvent. If the king wants his laws to apply to Levi, he'll have to makeit happen.

The time he is finally taken by the police, his gang gives him up for lost, but Levi is unshaken. He calmly explains to the uniforms, over the course of several hours, why he is not responsible, and even had he been responsible they could not charge him, and that this is all assuming a crime actually took place. When he is finished, he strolls out, leaving confusion in his wake. From that day on, he is considered something of a legend, and Levi finds that he likes it.

One day, a completely gratuitous fight with another gang is broken up by soldiers on horses. Levi finishes wiping the ground with someone twice his size, and looks up into a pair of disapproving blue eyes. He doesn't resist when they drag him away from the other thug. He knows better than to mess with soldiers. They aren't police, and will usually go for violence rather than legalese. He won't tell them his name, and he won't tell them where he lives. Eventually, they'll go away like the others, and leave this squalid part of town to continue tearing itself apart.

This commander, however, isn't in a hurry to leave, and fixes Levi with a look that reminds him a bit too much of his father.

"Why are you wasting your talents?" the blonde man says to him. "Your skill should be used to fight titans, not humans."

Your strength for-

Levi stares at him, mouth open, unable to ignore absurd similarities with a story he had learned –a bandit turned scholar, who became one of the greatest– and that's probably why he snorts and says, "I don't suppose you have a beautiful sister?"

The commander just looks confused, and Levi is reminded that he's not one of us. He agrees to join the Survey Corps anyway. People might pretend that the titans are safely outside the walls, but Levi has grown up knowing there was more to the world, and that no wall stands forever. He is ready to take on bigger challenges.

His parents aren't happy. Neither is his grandfather, now old and frail.

"If somebody's coming for you, kill him first," Levi says, and receives a cuff for his efforts.

"If you're going to quote, do it properly," his father says. But they let him go.

It is his first time as a cog in the wheel and not the decision maker, and he's not sure he likes it. He shares his room with others, and after the first time somebody touches one of his hoarded books Levi decides to get promoted to his own room as quickly as possible. The barracks are like the streets – it only takes a few rounds of beating up his fellow trainees before they understand he's not to be messed with. Unlike the streets, however, their commanders are quick to mete out justice to troublemakers. Levi explains, with great detail, how he has done nothing wrong, but apparently the officer is too stupid to follow the argument, and gives him punishment duty.

Erwin visits him, late at night, and he looks just as disappointed as he did when they first met.

"You need to learn to control yourself," he says.

"I am in perfect control," Levi responds. "I just do things differently."

Erwin nods, and Levi feels like he actually understands.

"Outside of the walls, we need people like you," Erwin says. "Doing things the same old way isn't getting us anywhere. Just get through this. Do it our way, and you'll earn the freedom to do it yours."

Levi looks at him in silence, then out over the sleeping camp he's stuck guarding from nothing at all because they're safe inside the walls.

"Okay," he says.

At meals, explaining that he can eat this, he can't eat that is too much of a pain, so he says he's vegetarian. He goes into the kitchen and terrorizes the staff to make sure it's clean and free of bugs, washes his hands before eating bread, and gains something of a reputation for being a clean-freak. Not entirely unearned, since now that he looks at the barracks he realizes how incredibly filthy everything is and his mother would certainly not approve of him living in this kind of environment. Nobody else seems to want to bother, so Levi takes it upon himself.

To everybody's surprise but his own, now that he's put his mind to it, he excels. Time after time he leaves the walls and looks at the world that's left, comparing it to the memories of his people. He fights titans for all of humanity that was destroyed and now lies dead and unremembered by the remnants. And he survives.

He thinks of his namesake, who with his brother once wiped out an entire city for insult rendered. Perhaps that Levi is proud of the fighter he has become.

Now the walls are shattered, the battle is on, and Levi's opinion of humanity has not risen in the face of their persistent denial. Luckily, his will to fight is completely independent of them and their approval.
The trainees get younger, and the deaths multiply. Time after time, Levi finds himself on an empty battlefield, the only one of his squad still standing. In other squads he hears people crying in fear, and doesn't understand what they're doing here with that kind of attitude. The people whose side he chooses to fight by aren't the sniveling cowards, but the ones who when they find themselves with the sea in front and death behind them, choose to leap forward.

He stands on a battlefield now, in the ruins of a no longer recognizable building, the sky far-off and hazy above him. Titans are in the distance, and the smell of blood and death scorches his nose. A persistent ache is starting in overworked muscles, but Levi loves that feeling. It means he's alive and fighting back. He takes a breath and prepares to rejoin the attack, when a cough from the side arrests his attention. It's Elli, bleeding heavily from somewhere Levi can't see, probably not long for this world. She says something with blood-flecked lips, and Levi heads towards her. He tries to stay with the dying as much as possible, reassuring them that somebody will remember, to the point where it's practically expected of him. Ignoring the filth, he kneels down, and listens to Elli's last words – and his mask of stone is shattered when Elli breathes out a phrase in a dead language that Levi hasn't heard anywhere except in his own home.

Without thinking, he gives the traditional reply, and their eyes meet in recognition.

"There are more of us," Elli breathes, and dies with a smile on her face.

Levi stands up and screams agony to the heavens. He leaps up the side of a building to the roof, looking across the destruction towards where Wall Sina stands, its name a bastardization of the holy place that was once there. "You said there wouldn't be another flood!" he cries, his voice cracking on words that nobody else would probably understand.

No response reaches him, not even an echo. The titans are still out there, his comrades are still dead, and the age of miracles is over. But on that rooftop, alone of his squad and maybe of his people, Levi chooses to believe that the promise stands. That no matter how grim things seem, they will have their victory in the end. One day he will stand on that wall and look at a world empty of titans, a future ahead of him, the past safe in his memories.

"This is my promise," he says, and before him lie split carcasses of titans, evaporating in the dull sunlight. The world is red. "Give me strength, and I will kill them all."

He does not hear a reply. But he has strength.

A few explanations of some of the references made:

1) Candles. It's customary to light candles for the Sabbath for the number of members in the nuclear family.

2) What Levi learns with his grandfather is Gemara/Talmud, 1,500 year old tractates of Jewish law that also contain anecdotes and legends. Most of it is in Aramaic.

3) Levi references the story of Reish Lakish and Rabbi Yochanan. Reish Lakish was a bandit whom Rabbi Yochanan convinced that his strength would be better used studying Torah, and allowed him to marry his sister. They were study partners for all their lives, and when Reish Lakish died, Rabbi Yochanan died shortly after from grief.

4) There is an idea that a person is permitted to kill someone who is attempting to kill them. Sanhedrin Tractate, page 72 side A.

5) The dietary restrictions are known as Kosher laws. Jews are only allowed to eat specific types of meat and it has to be killed a certain way, no blood, no bugs, no predatory birds, fish have to have fins and scales, no mixing milk and meat.

6) Levi's namesake would be Levi from the Bible, who was one of the Twelve Tribes of Israel.

7) According to the Bible, after the Flood God promised that he would never wipe out humanity again.

8) "Remember the days of the world." Deuteronomy 32:7. The command to learn history.

9) Death behind and the sea ahead - when the Israelites left Egypt, they stood on the shores of the Red Sea, with the Egyptians chasing him. Moses prayed to God to ask what to do, and He said that they should move forward. Nachshon Ben Aminadav was the first one brave enough to jump into the water, and then the splitting of the Red Sea occurred.

Thanks to anybody who reads, and cares about my crazy headcanons :)