What did Sylvia Plath mean when she wrote: 'I took a deep breath and listened to the old brag of my heart. I am, I am, I am'?

(This question is intended for the first session with students. After, the questions will be tailored to the texts they are studying, to focus on specific themes and contextual backgrounds. This exercise however stresses the importance of close reading, and developing the skills needed to delve below surface-level material.)This question is intentionally broad and invites us to dissect it as such. Every word must be taken into consideration, and how they gel against one another. For instance, let's look at 'the old brag of my heart'. The speaker listens to it - as though it is autonomous, or has a conscious of its own. The 'old brag' that it holds declares a history, a recurring state of feeling. Why it is bragging, we can only speculate with the passage given, but we may assume that the narrator yields to it, rather than listen to themselves (and, if the larger context of the book is known, we may look into how this plays into the themes of the novel as a whole).The sentence after, 'I am, I am, I am', makes effective use of repetition, as it mimics the cadence of a thumping heartbeat. Plath here stresses the re-evaluative state the speaker is in as she forces the reader to slow down with her, and contemplate alongside her. (Again, if the plot of the book was known, it is important to note that this soliloquy occurs right at the end of the book, and helps draw to a reflective end. Here, it might also be worth bringing in a little bit of historical context, and how that may effect the tone of Plath's words in general.)