act one's age, not one's shoe size

Verb

idiomatic imperative not one's shoe size usually

(idiomatic, usually imperative) Synonym of act one's age (“to behave in a mature manner; to avoid being childish”).

Japanese Meaning

年齢に応じた、成熟した振る舞いをする。 / 子供っぽい行動を避け、大人として相応しい行動を取る。

In the office manual, the guideline was simple: act one's age, not one's shoe size when interacting with clients.

社内マニュアルには簡潔にこう書かれていた：クライアントと接する際は年相応に振る舞い、子供っぽいことはしないこと。

Sense（1）

(idiomatic, usually imperative) Synonym of act one's age (“to behave in a mature manner; to avoid being childish”).

You should act your age, not your shoe size!

act one's age

（ canonical ）

acts one's age

（ present singular third-person ）

acting one's age

（ participle present ）

acted one's age

（ participle past ）

acted one's age

（ past ）