Some things are
worth keeping.
A sentence underlined. A thought in the margin.
The beginnings of a conversation.
Reading leaves traces. A phrase comes back to you on a walk. An argument changes the way you see something. You find a passage and know exactly who you want to send it to.
A commonplace book gives these encounters somewhere to live. What you keep becomes a record of what you noticed, and what you noticed becomes a way of thinking.
You don’t need to keep everything. Just enough to find your way back.