The writing is so beautiful! I can't find the proper words to describe it. It's perfectly ephemeral and soft -- like snow falling on your tongue, or sand running through your fingers.
As shown by the narrator, the way they write is dreamy and magical, the way a child views the world. Grasping for romantic descriptions and metaphors demonstrates just how much they cling to their youth, as much as they shame themself for being immature and childish.
The loveliness of the words against the despair of the narrator creates a wonderful contrast that truly conveys the longing, sincerity, and pitifulness of the author of the letter.
Overall, wonderful piece!