Project time forward to end a narrative essay. If the narrative took place ten years ago, you might write the conclusion from the perspective of someone who understands more now than you did then. Or you might write from the perspective of someone who is as baffled as ever.
If you take the perspective of one who now understands, be careful not to write a paragraph that sounds as if you are telling the reader what the moral of the story is. If possible, use sensory impressions to connote meaning rather than explain meaning. "Today I live in New York City. I didn't make time to visit my mother near the end of her life, so she died lonely" explains. But this creates meaning without explaining: "Today I live in New York City. I still remember my mother frantically waving goodbye, both empty hands flailing the air, on the day I left her for the last time."
Lead the reader into the conclusion with a final scene in real time as an alternative to projecting time forward. Describe a specific physical action or a final verbal exchange or a combination of those.
Avoid telling the reader how to feel. The conclusion of a narrative essay should resonate, not dictate. If you think of a movie about a character who overcomes adversity and emerges in triumph at the end of the narrative, you will notice that nowhere does the screenplay writer or director tell the reader to feel happy at the end. Instead the characters enact the end in a setting; we watch them, and thus we are transported to happiness. The end of a narrative essay can work in the same manner.
Include personal reflection in the conclusion, but avoid the temptation to explain everything. It's not necessary to answer all the questions a reader might have. Like fiction, a narrative essay may imply meaning rather than prescribe solutions. It's a sturdy genre that can work from metaphor, symbol and lyric language as well as describe and analyze.