Why you still picture them as who they were, years ago.

Someone mentions a person you both knew, and the picture that arrives in your mind is a specific, dated version of them — how they were at twenty-four, or during that one difficult year. You know, intellectually, that they've kept living since then. The picture doesn't update on its own.

A summary is easier to keep than a thousand corrections

Endel Tulving's distinction between episodic memory — specific, dated events — and semantic memory — generalized knowledge stripped of its original context — describes exactly what happens here.¹ Over time, dozens of specific encounters with a person compress into a semantic summary: she's the anxious one, he never follows through. The summary is efficient. It's also what gets consulted from then on, even after the specific episodes that would contradict it have quietly piled up.

Reconstruction defaults to the old draft

Frederic Bartlett's research established that remembering is reconstructive rather than a replay — assembled, each time, from whatever schema is already in place.² Without fresh, specific detail actively overriding it, reconstruction defaults to the existing draft. The draft, in this case, is a person who stopped being updated somewhere around the last time you paid close attention.

Confidence isn't evidence the picture is current

Ulric Neisser's analysis of John Dean's detailed, confidently delivered congressional testimony about long-running conversations — later checked against actual recordings — found substantial, systematic inaccuracies despite Dean's evident sincerity and detail.³ Confidence and accuracy are separate variables. A vivid, confident mental picture of someone is not, on its own, proof that the picture is still true.

The fix isn't to distrust every memory of a person. It's to notice when the last real update happened, and to keep updating deliberately rather than assuming the picture stays current on its own. Related: remembering your chats is not remembering your life and why "he's always been like that" is usually wrong.