Warning: This article contains spoilers.
There were a lot of theories about how Hodor became Hodor. Ever since Bran had a vision of the younger version of the sweet, barely verbal character - who was once a relatively talkative boy named Wylis - the speculation heated up. One of the most popular hunches was that Wylis, like Bran, could warg into animals, and his human self was mentally impaired after the creature he was inhabiting (Lyanna Stark's horse, perhaps) was killed.
Well, that didn't happen.
The truth was revealed during the most recent downer episode of Game of Thrones, appropriately titled The Door.
Bran and the Three-Eyed Raven are in the midst of a vision when the cave where they're hiding out is attacked by the Night's King and his White Walker army. As the zombies approach, one of the Children of the Forest tells Meera to save Bran. But when she runs into the cave to rescue him, his mind is stuck in the past leaving him unresponsive. Meanwhile, the always fearful Hodor is inconsolable.
In the vision, Bran is back at Winterfell watching a scene involving his father and grandfather. But he can hear the voice of Meera trying to wake him, and she's shouting at him to get Hodor to help. As he's done a couple times before, Bran - still standing in the past - wargs into Hodor.
And here's where things start to get weird. It isn't just Hodor's eyes that that turn white. Wylis's do as well.
As Hodor, in the present, grabs Bran and starts running, Wylis, in the past, collapses on the ground, apparently having some kind of seizure. Wylis can even hear Meera, as she yells at Hodor to "hold the door," in order to keep the White Walkers from exiting the cave and murdering Bran. Wylis starts echoing Meera, yelling the same phrase until it eventually morphs into just: "Hodor."
Seeing the poor kid on the ground having a breakdown is all very troubling but not nearly as disturbing as what happens to present-day Hodor, who sacrifices himself to save Bran and Meera. We're going to miss the big lug.
In any case, this means (maybe?) that Bran caused Hodor to become Hodor, even though Hodor became Hodor before Bran was born.
Now would be a good time to mention that this episode of Game of Thrones was directed by Jack Bender, who also directed dozens of episodes of the mess-with-your-mind fest Lost.
And all of this is especially confusing since the Three-Eyed Raven told Bran a couple episodes ago that, "The past is already written. The ink is already dry."
Isaac Hampstead-Wright, who plays Bran, actually teased the time-traveling bit a few weeks ago during an interview with Hollywood Reporter, when he said: "We all know from 'Doctor Who' that if you start messing with time, things go wrong."
Well things have definitely gone very, very wrong. Bran is now down to one ally. Plus he's given viewers a serious headache.