Each stanza here is spoken by a different abstract idea: silence, the dark, time, trust and feelings. Each one describes itself as something that can help or hurt. Silence can be the sign of a friendship that has quietly failed. The dark hides the unknown and can grow as easily as a light switches on. Time can heal or heartbreak. Trust is fragile, and once broken it is never quite the same. Feelings can fill a person or leave them numb.
Only in the final stanza do we learn who is really speaking: "I am afraid." The speaker seems to be fear itself, or someone haunted by it, and each earlier voice was one of its disguises. The mood is uneasy and quietly sad, with a repeating pattern that feels like a worry circling in the mind. The last line lands hardest: "All my fears were taught." The poem suggests fear is not natural but learned, often from painful experiences with other people.