The science of early childhood memory is specific about this: episodic memory — the kind that stores narrative, sequence, cause and effect — does not reliably form before the age of three and a half, and even then only in fragments. What a four-year-old retains is not a story. It is an atmosphere. A sensation. The emotional residue of something that happened before the brain had the architecture to record why.

AJ is fifteen. He does not talk about what he remembers from that night. He has not talked about it with Clementine, not once in eleven years, and Clementine has not asked. This is an arrangement they arrived at without discussing it, the way certain things between people who have survived the same thing calcify into unspoken agreements. He knows she knows he remembers. She knows he knows she knows.

What AJ actually retains from that night is not what you would expect. He does not remember the sound. He does not remember being cold, though it was cold. What he remembers is a quality of light in a doorway — the specific orange of a lamp through a curtain — and the feeling of being carried, and a smell that he has spent eleven years not being able to name. He has been in three buildings since then that had that smell. He left each one quickly.

The choice Clementine made that night has a shape in AJ's memory even though he did not see it being made. It exists as an absence — a before and an after with nothing in between, a cut in the film where something happened that changed the texture of everything that followed. He has never asked her to fill in the cut. He is not sure, at fifteen, that he wants her to. He is also not sure, at fifteen, that he can keep not wanting that.