One dropped letter does most of the work in "Lacuna". Spelled down the page, B-A-N-K is "blank" with its L missing, and a lacuna is exactly that: a gap, a missing piece, like the hole a reader finds in a damaged manuscript. It is hard not to notice that the missing L is also the first letter of the title. The poem doesn't only tell us about emptiness. It shows us a word with a hole in it. Its central idea is numbness, and the uneasy question of whether feeling nothing can count as getting better.
The opening lines set up the trap. The speaker sits "with an expression", and in the next line the word comes back: "The expression that is not only plastered onto my face but the one that is also plastered onto my emotions." Expression should mean showing what you feel, but here it means the opposite, a fixed look that shows nothing. "Plastered" suggests something slapped on and left to set, like a wall hiding what is behind it. The second half of the line is the unsettling part. A mask normally covers real feelings underneath, but this one has spread inward until the speaker's emotions are covered too. The line itself is the longest in the poem. It sprawls and stacks its clauses ("not only... but also"), as though the mask keeps getting another layer.
Then the poem nearly stops. B, A, N, K each get a line to themselves, and the reader is forced to slow down and take them one at a time, like bricks or drips. We have to assemble the word ourselves, and when we do, something is wrong with it. The spelling is incomplete, and in that sense the form acts out the meaning. The speaker's language has lost a piece, just as the speaker has lost the ability to feel. A reader could also hear a different word in "bank", something solid and flat that you sit beside. I read the missing L as the stronger idea, because the title points straight at it.
What follows is the plainest line in the poem: "All I feel is nothing." Nearly every word is a single syllable, and nothing in it is decorated. It is also a paradox. To "feel" "nothing" is still to report a feeling, so the numbness has to be described with the very word it denies. There is no rhyme anywhere in the poem and no steady beat. The lines swing from sprawling to single letters to short statements. This is free verse, and the lack of pattern suits the subject, because nothing chimes or resolves.
The ending is where the poem becomes most interesting. "I thought I was getting better" is in the past tense and sounds almost sure of itself. The next line immediately starts to backtrack: "Well actually I guess in a way I am..." Three softeners are stacked together ("actually", "I guess", "in a way"), and the ellipsis leaves the thought dangling. The speaker seems to be arguing with herself or himself mid-sentence. There are at least two ways to read this. Perhaps the pain really has eased, and numbness is what is left once the worst has passed, which is a kind of progress. Or perhaps "better" only means better at wearing the plastered expression. The poem doesn't choose, and that refusal is the most honest thing about it.
The poem is significant because it captures a feeling that is hard to put into words. Many poems about sadness are full of storms and tears. This one is about absence, the flat state where there is nothing to cry about because there is nothing there. It makes that absence visible by cutting a letter out of a word and letting the white space on the page do some of the speaking. For students, it is a useful example of how form can carry meaning, and of how a poem can end with a doubt that doesn't resolve and still feel finished.