Robert Frost is one of the most popular modern American poets. Because his career as a writer began to take hold just after the turn of the century, he can be considered one of the 20th century's greatest poets. His work is widely anthologized and taught at all levels of education. One reason Frost's poems can be taught to students of a wide age range is that the language he uses is generally fairly simple. This is one aspect of his work that sets him apart from other modern poets working in the early 20th century. But despite the use of simple language, Frost often conveyed complex ideas in his imagery and settings. Some of his poems seem to be simple descriptions of outdoor activities (such as "After Apple Picking") or fairly uneventful journeys (as in "The Road Not Taken"). And images of nature are also prominent in Frost's poetry, earning him a reputation as a nature poet. But in many of his poems, Frost explores ideas about the human condition, in particular the arc of a person's adult life and career, and their attitudes towards death.
Lines like "I have promises to keep, and miles to go before I sleep" (from "Stopping by Woods on a Snowy Evening") have layers of meaning. At face value, the narrator is simply stating that he has an engagement and must hasten on his way to meet the people waiting for him, and has a long way to go before his night ends. But the poem can also be read as a meditation on how one approaches the later years of one's life: deciding to live life to the fullest before the inevitability of death.