Before the internet, before the index card, readers kept a commonplace book: one notebook, kept for years, into which they copied anything worth keeping. Quotations, recipes, arguments, a good insult, the name of a decent doctor.
Milton kept one. Locke kept one and published a method for indexing it. Marcus Aurelius, arguably, left us his.
Why copying works
Typing a passage into an app takes four seconds and leaves no trace. Copying it out by hand takes a minute and leaves the sentence somewhere in your body. The friction is not a bug to be optimised away. It is the mechanism.
You also cannot copy out everything, so the notebook forces a judgement at the moment of reading. That judgement is the skill.
The rules that keep it alive
One notebook at a time. Date every entry. Never reorganise it.
That last rule is the one people fight. A commonplace book is chronological, not thematic, and its disorder is the point. Flipping through six months of unrelated entries is how you find the connection you were not looking for.
A notebook you have to maintain is a notebook you will stop keeping.
What goes in
Anything you would be annoyed to lose. A line from a novel. Something a friend said in a pub. The way a stranger described their job. Three words you liked the sound of.
Do not write about your day. That is a diary, it is a different instrument, and mixing the two kills both.
Start tonight, with whatever notebook is already in the house. The first entry is always the hardest and it does not have to be good.
