He has a warehouse of notecards with ideas and stories and quotes and facts and bits of research, which get pulled and pieced together then proofread and revised and trimmed and inspected and packaged and then shipped.
While the ancients thought of the commonplace as a storehouse of value or a treasury, modern knowledge workers and content creators might analogize it to a factory where one stores up ideas in a warehouse space where they can be easily accessed, put into a production line where those ideas can be assembled, revised, proofread, and then package and distributed to consumers (readers).
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