Used to allude to something unsaid or hinted at.

(formal or humorous) A question asked to know the reason for being visited by the interlocutor.

(informal) An expression used to point out that another person's joke or cleverness has been recognised or understood, either to acknowledge its cleverness or alternatively to communicate a lack of amusement.

(colloquial) You are familiar with the situation I am describing; used to establish common ground with the interlocutor

(idiomatic, Britain, Ireland) To do what is described or what one would expect, with no further explanation needed.

A rhetorical question used to indicate that the speaker is feeling left out or slighted by attention given to another person or persons.

(rhetorical question, sarcastic) A phrase sometimes given as a retort to someone who has done something unsurprising or unimpressive and has seen fit to inform one of having done so.

In commercial transactions, the quality of goods and services increases as the prices increase, i.e., the more one pays, the better the merchandise.

A person's actions, whether good or bad, will often have consequences for that person. / The status eventually returns to its original value after completing some sort of cycle.

Literally, what is good for a female goose is equally good for a male goose (gander); or, what is good for a woman should be equally as good for a man.