It is important to determine the cental idea of a speech or essay so that you can better understand the entire speech/essay. Then in the end when you understand the entire speech/essay you can use it to help you through life and maybe learn something from it.
It is important to identify the central idea of a speech or an essay as it helps the listener/reader understand the meaning and objective of the entire piece. Otherwise, losing oneself in the meaningless gibberish of the speaker/author is very likely, as for one is hard to find interest in something that virtually is going nowhere.
Once the central idea is identified, it is easy to go along the main topic and subtopics, as well as formulating one's own conclusions at the end.
Well, since you didn't include the excerpts, I cannot possibly know which ones you are referring to, but overall, Dickinson used iambic tetrameters and iambic trimeters in this poem.
