have one's bread buttered for life

a little bit of bread and no cheese

Used to represent the song of the yellowhammer (Emberiza citrinella).

abound in one's own sense

To follow one’s own inclinations and opinions.

ace up one's sleeve

A surprise advantage of which others are not aware.

act one's age

To behave in a manner appropriate to one's age.

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

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

afraid of one's own shadow

Exceptionally timid.

air one's dirty laundry in public

To reveal one's sordid secrets to the public.

air one's dirty linen in public

Synonym of air one's dirty laundry in public.