What does it mean that context belongs with the atom?

An atomic note should carry enough context to be understood without its original source.

Example: You highlight a sentence from a book: 'The map is not the territory.' Six months later you find it in your notes. Which map? Which territory? Was Korzybski talking about semantics, was it Bateson on epistemology, or was it your team lead quoting it in a meeting about architecture diagrams? The sentence is identical in all three cases. Without context, it's a fortune cookie. With context — source, date, why it mattered to you, what you were thinking when you captured it — it's a usable building block.

Try this: Open your notes app and find a note you wrote more than three months ago. Read it cold, as if someone else wrote it. Can you understand what it means, why you wrote it, and what you were supposed to do with it — without opening any other document? If not, rewrite it right now: add the source, the date, one sentence about why it mattered, and one sentence about what it connects to. That's the minimum context an atom needs to survive on its own.