Read someone like a book

Meaning

Understand someone easily.

Usage

Used when a person seems transparent.

Origin & History

Origins and dates here are approximate summaries. Many idioms have disputed or unknown origins, and not every date has been checked against a historical dictionary, so treat specific dates and stories as a starting point rather than a citation.

Books can be scanned for meaning; similar to people.

Became common with rising literacy in the 19th century.