Ok, this is one of my favorite quotes from Les Mis, so headcanon time!!!
When Grantaire starts going to Les Amis meetings, he doesn’t exactly believe he is one of them–he always feels slightly like no one actually cares if he’s there or like he doesn’t actually fit in and belong, and it doesn’t help that he and Enjolras are always at each others throats, so at the end of one night when he’s had a little too much to drink, he starts softly venting all of this to Bossuet. Of course Bossuet listens to Grantaire and tries to comfort him, but Grantaire still can’t shake that feeling…
What Grantaire doesn’t know is that Enolras heard everything. So, yes, Enjolras works on being nicer to Grantaire during meetings, but he also takes a green post-it note and writes on it in flawless calligraphy “J’en suis” and at the next meeting subtly slips it into R’s bag, who doesn’t notice it until he gets home, but smiles none the less and begins to think maybe he does belong there after all.
From then on, Enjolras always carries that green post-it notepad in his bag, and whenever he can see that R is having a bad day, he manages to somehow write “J’en suis” on a post-it note in perfect calligraphy and slip it into Grantaire’s bag–all without anyone noticing. Grantaire won’t tell anyone, but those post-it notes have helped him through some pretty tough times, and he keeps every single one he gets.
Courf drags Marius along to Les Amis one day, only to have Marius be dragged by Ferre’s “to be free” (you all know the scene), so at the end of the meeting Enj asks an angry, exasperated Marius to give their meetings one more chance, and at the next one is a purple post-it note waiting for him at the same empty table he had sat at last time. The note reads “J’en suis” in perfect calligraphy.
When Musichetta joins there’s an obnoxious neon green post-it note for her, while Eponine gets a soft teal, and Cossette gets a bright pink one.
It slowly starts to spiral into something larger.
Whenever Joly has a panic attack or his leg is acting up, there’s a post-it note waiting for him, light blue with the phrase “J’en suis.”
Whenever Feuilly hasn’t been to a meeting in over a month due to his jobs, there’s “J’en suis” on an orange post-it note waiting for him.
When something goes wrong, which happens a lot with Bossuet’s luck, or when he gets mad at himself for screwing something up, there are post-it notes with lucky shamrock backgrounds and the famous “J’en suis.”
When Jehan comes out as non-binary, they get a purple one (their favorite color), with “J’en suis” written over a background of flowers.
Bahorel gets one when he finally decides stop following his parents’ dream that he would be a lawyer and starts to follow his own dream of opening a patiserie.
Everyone else is weary when Jehan starts to bring Montparnasse along to meetings, and he almost decides he isn’t coming back, until he feels Enjolras slip something into his pocket (of course he knows it’s Enjolras, he is a master pick-pocket and Enjolras would have to be ten times better to fool him), and when Parnasse takes it out, there’s a black post-it note with “J’en suis” in red pen. He never tells anyone it’s Enjolras, but when he comes back to the next meeting he greats Enj with a rare smile, as an attempt to thank Enj for the note.
Speculations about the mysterious note-giver goes around, and when Enjolras is quickly ruled out–because there’s a reason Combeferre takes notes at meetings, and that reason is partially because no one can read Enjolras’s disastrous handwriting–Enj just smiles, knowing his secret is safe.
Only Combeferre and Courfeyrac know it’s Enjolras, and that’s only because they live with him and have to deal with the fact that their appartment has become over-run with pads of post-it notes. Plus Courfeyrac is the only person in the world Enjolras would go to for ideas on which post-it notes to order for each person.
After a particularly bad day, Enjolras silently sneaks out of a meeting early. When R finds him crying on the fire-escape, he doesn’t say anything, just slips a red post-it note into his hand as they continue to stare up at the stars in silence. When Enjolras finally dries his eyes enough to read it, he sees “J’en suis” scribbled across it in Grantaire’s chicken-scratch. That’s the moment Enjolras realizes he likes Grantaire.
Fast forward a little, and still no one knows who the secret note-giver is, but that doesn’t matter anymore. What matters most is that these notes have helped everyone through some horrible times, so Grantaire has the idea to get a tattoo of the mysterious writing. Bahorel, Jehan, Bossuet, Musichetta, Combeferre, Eponine, and Cossette–and Enjolras–all want to do the same thing, so they all go as a big group, but it’s only a week later when Grantaire realizes the tattoo Enjolras got wasn’t “J’en suis” in flawless calligraphy like everyone else’s tattoo–it was the same scribbled “J’en suis” from that night on the fire-escape.
Fast forward a little more, and after they have been dating for a few years, Enjolras gets down on one knee and proposes to R with a ring bearing the inscription “J’en suis.”