(rhetorical question, colloquial, sarcastic) A comment used to indicate that a previous comment is irrelevant or unimportant.

(informal) Used as a rhetorical question to confirm agreement, knowing or understanding at the end of a statement.

It is better to do something oneself than to rely on others to do it well.

(rhetorical question, colloquial) Used to indicate that a previous comment is irrelevant or non sequitur.

Alternative form of damned if one does and damned if one doesn't

When finding oneself in a troubling situation, one should first make sure one is not making the situation worse by his own actions before addressing all other causes.

(colloquial, sarcastic) A rhetorical question used to discourage the interlocutor from blind obedience.

Alternative form of if someone told you to jump off a bridge, would you do it

Do not procrastinate whatever that can be done today until tomorrow.

Synonym of if you find yourself in a hole, the first thing to do is stop digging