Time... Time is money... Timing is everything... Time! Time is one of the most important unseen factors that run our lives: we tend to make daily schedule depending on the time at which the public transit stops in the vicinity of our homes; we build our lives around timing and time; the movement of clocks on our walls and watches on our hands - tick-tock, tick-tock, and the sand will run out of each individual clock - after all, if we tend to build our lives around time, then it is only natural that for each of us time will run out. Sadly, nobody tends to realize this, but in the earlier times... well, that was different.
One of merry old England's greatest bards, Shakespeare, certainly had a healthy respect for Father Time. In his sonnet 73, speaking as an old man (perhaps approaching a younger, possibly a much-younger lover), he talks about the time limiting the human life, that the human life must come to an end, and the nearer it comes to it, it gains momentum - first the bard talks about a tree under the flow of months and seasons, then about people under the flow of hours during a day-and-night (and already there's the rather broad hint about the unavoidable death), and finally about a bonfire - something that lasts for few hours on the average. Fundamentally, what Shakespeare is trying to say is that in the terms of time human life is a very small thing - almost like a bonfire that has only so much time before dying out and dissolving into embers and ashes. However, the sonnet ends on a somewhat optimistic note: "This thou perceiv'st, which makes thy love more strong / To love that well which thou must leave ere long". In other words, he's saying that he knows that human life is fleeing and that he in particular is going to die quite soon (especially compared to his love). But, since the end is so near, then their feelings for each other have never been this strong before; to re-make an old proverb, this is the brightest hour before the sunset, after which the sun will never rise again.
Thus, sonnet 73 ends on an optimistic note: even if human life is fleeing, let's make it worthwhile instead.
In sonnet 18, on the other hand, the bard is actually challenging death, and promising the object of his affections sort of immortality: "... So long as man can breathe, or eyes can see, / So long lives this, and this gives life to thee". In other words, the poet challenges death over the life of his lover: he promises her immortality, he is rescuing her from obscurity which is actually the ultimate death - to be forgotten in time by everyone, and obviously he succeeds, as this very sonnet is the statement of both her existence and his feelings for her - as long as there are people reading his sonnets, they will remember both the bard and his love.
In short, the Elizabethans had really a healthy respect for time and a very clear understanding that as long as people remember a person, he or she still lives in a fashion. If St. Vincent Millay is any indication, then their 20th century descendants differ from them as earth differs from the sky. Take her poem, "If I should learn, in some quite casual way". It, too, is about time and death, but her look at them is quite different from Shakespeare's; and yet... Shakespeare's view indicated that compared to death, life was a very small, fleeting thing and consequently, life was very precious. And so's love - it is even more precious, because it makes the life worth living. That was Shakespeare. And now we have St. Vincent Millay. Where Shakespeare's poetry is nature and allegory, hers is stark realism; it could have been easily written now, instead of 1917. And the contents... "If I should learn in some casual way <...> a hurrying man, who happened to be you, / At noon today had happened to be killed"... In other words, just like Shakespeare, St. Vincent Millay is writing to, or about somebody whom she knows - i.e. if he "had happened to be killed", "I should not cry aloud--I could not cry ... I should but watch the station lights rush by / With a more careful interest on my face..." Where Elizabethan Shakespeare told how life was a fragile thing, and that people should treasure it and love, 20th century's St. Vincent Millay too, agrees that human life is very easy to break; but that's where the similarities part way. Shakespeare's sonnets tend to end on an optimistic note (73), or are optimistic (18); St. Vincent Millay's poem is quite pessimistic. For St. Vincent Millay only the lives of whom she actually knows matter - all those if's and should's in the first lines of her poem tell the reader, that if she had read the obituary of some stranger, she wouldn't really care. And the second part of the poem tells us, that since to other people her dead friend is some stranger, they don't care - and thus, should she want to express her grief out loud, this would not be condoned (the year is 1917, not 2005 after all). Thus, she's forced to remain nonchalant and act as other people do. And to what does that lead?
Consequently, it led to the fact that whereas in Elizabethan times a human's world was, well, the world, nowadays it has pretty much shrunk to one's family, family friends, and possibly some close colleagues at work. That obsession with time is leading us to act like robots, machines, and that is not good. In Elizabethan times a man was the king of the world; nowadays he's nothing more than a cog in a greater machine. Surely some decent middle ground can be found? After all, all poets agree that human life is very fleeing and that everybody depends on each other to be remembered - and that is something worthwhile to keep in mind - that as long as a person is remembered, he is never permanently dead.