The sun rises and sets and hurries around to rise again. When we make earthly pursuits are sole or ultimate aim, sooner or later we will come to an understanding of the futility of our position. This is because no earthly achievement or goal can ultimately satisfy. By nature earthly pursuits remain locked in the transitory place of sense experience and appreciation. And all of us instinctively know they must eventually pass away into dust.
History merely repeats itself.
It's used extensively by Paul in the New Covenant epistles. I like to use it, since once its meaning is grasped by reader or listener, upon seeing it they'll understand instantly that I'm relating about the difference between things earthly and spiritual. Here the passage speaks of the fact that two sense experiences, sight and sound, are unable to confer contentment. This is much along the lines of the previous commentary. The main point here is that sense experience and spiritual experience are as different as swimming and flying.