The speaker takes his remaining fifty years and states that they still represent “little room.” Together with the use of “only” earlier, the speaker presents his life as limited in terms of time and space. He is essentially saying that fifty years is still not enough time to truly appreciate all the beauty in the world, much less just the loveliness of the cherry trees.
Changing seasons are often used in poetry to metaphorically describe the stages of a person’s life. Spring is youth, summer is adulthood, fall is middle age, and winter is old age. By “snow” the speaker suggests that he will look at nature in all seasons, winter included, because there is too much to see and appreciate with his limited time. However, he also metaphorically means that he will continue to go out and look at the cherry trees into his old age.
