I felt a Funeral, in my Brain by Emily Dickinson (1861)

The mind has gathered to bury itself. Boots cross and recross a floor that is also the brain, mourners treading until the very capacity for sense begins to give way, and Emily Dickinson asks you to attend a funeral where you are at once the watcher in the pew and the body in the box. The service beats like a drum until thought goes numb. Then they lift the coffin and creak across the soul in boots of lead, and the whole of space starts to toll, all heaven a Bell and all existence narrowed to a single wrecked Ear, alone in a silence louder than any sound. What makes the poem unbearable is that it never explains; it only enacts, the tidy hymn-meter keeping its measure even as a Plank in Reason breaks and the speaker drops, hitting a World at every plunge. Dickinson ends on a dash, mid-fall, at the precise instant knowing stops. You finish where she did, with the floor gone and the sentence still open.