The poem that best fits the description of celebrating the joy and pleasure of a beautiful memory, especially a scene from nature, is:
"I Wandered Lonely as a Cloud" by William Wordsworth.
In this poem, Wordsworth describes the beauty of a field of daffodils and how the memory of that scene brings him joy and comfort even when he is feeling lonely or down. The poem celebrates the power of nature to uplift the spirit and create lasting positive memories.