I Felt a Funeral, in my Brain

I think the central theme of this poem is that the person who is hearing the funeral is really going insane. The readers sees that the person does not feel or see his or her own funeral but hears it. So we the reader automatically assume the person is inside the casket. When the person's "mind was going numb" I took that as a sign of the signs of one's sanity to also go. I thought this meant his or her sense of reason was starting to go. I also thought that the viewers were symbols of the sympathsizers who see the insane not really as people. But the "a Plank in Reason, broke" I took this as a realization that one was being insane. This realization is the "Finished knowing-then-". This poem's central theme was of the happenings of what will happen when one becomes insane and what the thoughts or feelings are to that person.