Shamshin emphasizes that these natural phenomena are short-lived. If you don't go to the woods today to see the bird cherry in bloom, tomorrow the petals will have fallen. The "performance" will be over, and you will have missed it forever.
The opening where the author invites the reader to witness a specific natural event (like the blooming of trees).
Ultimately, Shamshin’s message is an appeal to the soul: stop rushing through life and start rushing toward the quiet, magnificent "holidays" that nature throws every day.