To behave in a manner appropriate to one's age.
play with a full deck
To behave in a manner suggesting that one is of normal intelligence, a …
charm the birds from the trees
To behave in a very charming manner.
strut one's stuff
To behave or perform in a showy or ostentatious manner, as if to impre …
play it straight
To behave in a manner that is straightforward, honest, or sincere.
wear out one's welcome
To behave in an offensive, burdensome, or tiresome manner, with the re …
lose the plot
To cease to behave in a consistent or rational manner.