In someone's good books

Origin

For centuries, administrators, teachers, and masters alike kept meticulous ledgers, recording everything from attendance to behavior, debts to favors. To be "in someone's good books" once referred to the literal act of having your name inscribed in such a register, signifying that you were a favored employee, a diligent student, or a trustworthy associate. This tangible record of positive standing, whether it was a merchant's clean account of a reliable customer or a monarch's private list of loyal courtiers, was a clear mark of approval, promising preferential treatment or reward. The phrase thus evolved from these physical registers, capturing the essence of being held in high esteem and promising a favorable outcome.