Warning: Spoilers ahead for Game Of Thrones.
A lot of information was thrown at us during the season 7 Game Of Thrones finale, and to be honest, I've forgotten pretty much everything that isn't Jon Snow's (Kit Harington) butt, except for, obviously, the confirmation of the big reveal that Rhaegar Targaryen and Lyanna Stark were married, making Jon Snow their legitimate son and the heir to the throne.
But how did we get here? The R+L=J theory has been floating around for a few seasons, but it didn't just come out of nowhere. The books, which inspired the series, keep detailed records that HBO just cannot fit into the episodes, and they include exactly how Rhaegar and Lyanna met, unknowingly tangling a web that would continue to cause problems for years and years after their death.
A Buzzfeed video does an amazing job breaking all of this down, starting with Rhaegar's original marriage to Elia Martell, sister of Oberyn Martell. They share two children, Rhaenys and Aegon. (Lotta vowels.) At the same time, Lyanna, who is Ned Stark's sister, is betrothed to Robert Baratheon, who we met in season 1 as Cersei's husband.
Fast forward to the Tourney of Harrenhal, where all of these characters come together. There, Howland Reed (for purposes of this story, he's just a dude, go with it) is mercilessly bullied, and only Lyanna comes to his aid, caring for his wounds and taking him to a feast, where she sees Rhaegar for the first time. He's musical and brilliant and she falls in love instantly, yada yada.
But! She's still focused on getting revenge for Howland Reed, so readers believe she assumed the identity of the Knight Of The Laughing Tree who ultimately beats the squires who were bullying Howland. This is relevant because this made the Mad King (Rhaegar's dad) super angry, and he ordered Rhaeger to go find The Knight Of The Laughing Tree. If the Knight's true identity is Lyanna, we can assume this is how they met, which would explain what happens next.
Rhaeger ultimately wins the tournament, and when he goes to crown the Queen of Love and Beauty, he goes right past Elia and gives it to Lyanna. Yikes!
Time passes and they run off together, leading to the events confirmed by Sam (John Bradley-West), Bran (Isaac Hempstead Wright), and most notably, GILLY (Hannah Murray), in Sunday night's finale. But this is how it all started, and even though there's just one season left, it still feels like we're far from the end.