By repeating the line, "[a]nd miles to go before I sleep," the speaker sets up an intrigue that cannot be assuaged by the reader or the critic alike. The poem, however, does not support the contentious notion that the speaker is contemplating suicide, as some have speculated. On the other hand, there seems to be no reason that speaker seemed to snap out o his hypnotic trance brought about by the beauty of the scene: the dark and deep woods filling up with snow has been alluring. But the speaker suddenly and without obvious provocation is yanked back to the reality of his having many miles to travel before getting back to the place where he has "promises to keep."
The poem does suggest many questions: Why does the speaker mention that the owner of the woods won't see him? Why does he speculate about what his horse must think? Why does he repeat the last line? Why did he stop in the first place? These questions cannot be answered by the poem, and because Robert Frost called his poem, "The Road Not Taken," "a tricky poem," the reader will likely wonder if he also thought of "Stopping by Woods on a Snowy Evening" as a tricky poem.