to the manner born

if you behave to the manner born, you behave confidently, as if a particular situation is usual and familiar for you Although he never lost his lower-class accent, he lived the life of a rich and successful businessman as to the manner born.

Accustomed from birth to a particular behavior or lifestyle, as in At a high-society function she behaves as though to the manner born, but we know she came from very humble circumstances . This term was invented by Shakespeare in Hamlet. Referring to the King's carousing in Danish style, Hamlet says (1:4): "Though I am native here And to the manner born, it is a custom More honor'd in the breach than the observance." The manner in this expression was later sometimes changed to manor, "the main house of an estate," and the idiom's sense became equated with "high-born" (and therefore accustomed to luxury), a way in which it is often used today.

Accustomed to a position, custom, or lifestyle from or as if from birth.