Four short lines carry a quiet kind of hurt. The speaker describes trying to be heard and failing: "No one listened." The next line, "So I gave up," treats giving up as the natural result, not a dramatic choice. Nobody storms off or shouts. The speaker simply stops trying.
What stands out is how little the poem says. The lines are brief and plain, and the final word, "Silence," is trailed by a row of dots that seems to let the quiet go on after the poem ends. The break in "I just sat there in / Silence" also makes us pause before the last word, as if we are sitting in it too.
The mood is flat, tired, and lonely. The speaker doesn't sound angry so much as worn out. The word "just" suggests resignation, and the poem leaves us with the sense that being ignored can feel worse than an argument.