The idiom "on your mark" means that someone is ready or prepared to do something, and they are waiting for the signal to start. It can also mean that someone is focused or determined to achieve a goal or complete a task.

The idiom "part brass rags" refers to someone who is very poor or has low social status. It's a figurative way of saying that the person has nothing left to offer and is almost destitute.

The idiom "at the helm" means to be in charge or in control of something, often referring to a leader, captain, or person who is making decisions.

The idiom "kill the goose that lays the golden egg" is used to describe the situation where someone takes an action that destroys a valuable resource or opportunity. It is often used when someone has been successful and then loses everything because of their actions.

The idiom "blow one's mind" means to be amazed or shocked, especially by something that is unexpected or surprising. It can also mean to be completely stunned or overwhelmed by something. The idiom is used in both positive and negative contexts, depending on the person's reaction.