Domin Sweet's short poem begins with a plain confession: the speaker is afraid of two things, not understanding and being alone. There's no elaborate imagery here. The speaker simply says it, and the bare wording makes the admission feel honest and a little exposed.
The layout helps. Each fear is indented further than the one before, so the lines seem to step downward, as if the speaker is sinking into the feeling. The two fears also connect. Not understanding can be isolating, since it leaves you shut out from other people or from sense itself, and being alone can make the world harder to understand.
The last line turns the poem sadder. The speaker doesn't know why they feel this way, and believes no one shares the view. That adds a third layer: the fear of being alone is repeated in the very act of confessing it. The mood is quiet, vulnerable, and a bit lost, like someone speaking softly to see if anyone answers.