This is another way of engendering hope and celebrating life even when there are traces of warning and of darkness ahead. Man cannot but lose with death, and yet he can make most of his hay days to die without regret. And that is a cavalier's way of uttering a Donne like conceit with the lines: (from Death be not Proud; Holy Sonnets: X)
Similar threats have been mellowed down with Shakespeare's sonnets with his optimism to conquer death with truth, love and beauty. Sometimes to him Death was not a physical death but a death in life as in Sonnet 73 where he speculates his coming death and yet feels dead at the same time like "Bare ruined choirs," an escape (Sonnet 66, "Tired with all these, for restful death I cry"), or Sonnet 55 vouching an undying "living record" of his lover's memory, in the "eyes of all posterity and dwell in lovers' eyes"! This idea of cheating melancholy, and eternal note of human sadness heard from the days of "Sophocles" through what Matthew Arnold hears and concludes in his poem "Dover Beach":
This is Arnold's way of giving his fears and turmoil the only antidote, for he is helpless in a world swept by such helpless inevitable destiny of mankind.