Not long ago, Ted made his facebook status, "this too shall pass" and, of course, I assumed it was some hardship or bad event at work. After I asked him about it, he had me listed to Ajahn Brahm- http://www.ajahnbrahm.org/- a Buddhist Monk that Ted listens too. I particularly like him because he a) has a background in theoretical physics from Cambridge, and b) in his lectures/talks he seems to take the long way around, with several tangents and jokes and stories, and it keeps my attention.
On this day, this particular talk was about how all things are impermanent. I'll spare you the long details, because I don't want to get anything incorrect or mislead you, but the overall jist was just that all things will pass, everything is cyclical. While the bad times will eventually go away (which is normally when people tell you that "this too shall pass") and you can be relieved that it has to eventually get better, when the times are great, you must remember that this too shall pass.
Oddly enough, I can't get the phrase/idea out of my mind. If you prepare, when things are great, for when they aren't so great, maybe they won't be so bad, and you can get out of the valley faster.