This poem immediatly informs you that it is an older person speaking to a younger lover. The sonnet contains three powerful metaphors that symbolize the end of his life. The first, the season of fall, portrays his life as cold and bare. The second, twilight, represents the end of a day where darkness implies death. Finally, the fire, almost extinguished, is like life, almost out. What once was fuel, now is ash. This imagery helps to prove his point that his age difference makes their love stronger and that the younger lover should love as much as they can before time runs out.