For me, the essence of this passage is a central teaching in Buddhism: the law of impermanence. It is an inescapable, eternal truth. Nothing lasts, neither good nor evil. Click here for a short treatise on the concept which includes the following:
Shoud [sic] we understand and recognize the Law of Impermanence, we could change our perspective toward life. We would admit life as it is, no matter what kind of change or adversity we encounter. That is the teaching of Buddha. We would be brave and wise in any circumstance, and more sympathetic to others. Never again would we cry when facing a mishap, an illness, or even death.
A dangerous misinterpretation of the law of impermanence can lead to a nihilistic view of life. If nothing lasts, then fuck it. Since it's all meaningless, since everyone and everything I care about will be destroyed, why give a shit about anything? On the contrary, understanding the law of impermanence brings great meaning to one's existence; as described above, it allows us to change our perspective and face adversity bravely and wisely and become more sympathetic (I would change that word to empathetic) to others. Understanding the law of impermanence is an important step toward ending our own suffering.
In The Matrix, the Oracle tells Neo: "Everything that has a beginning has an end." That goes for the good stuff and the bad stuff in your life. Knowing this, we can fully appreciate the good stuff while it's happening, and bear the bad stuff because we know it will end.
My mom always said, "This too shall pass." I think she usually said this about bad stuff, but it still sums up the law of impermanence pretty well.
Of course, the concepts of "good" and "bad" emanate from judgments we ourselves make, and if we would simply observe without the "me" involved (see yesterday's post), we'd end conflict right at the source.
Some will say, "If Jack understood all this stuff, why did he end up a disillusioned, bitter alcoholic?" My retort: That says a lot more about the speaker of such a statement than it does about Jack. If you want to change the world, start by changing yourself. If you're going to wait until others are perfect, you'll wait for an eternity. Jack was pointing at the moon, but he wasn't the moon and never claimed to be. He gave us the terrible beauty of the world in his words, and for that, those of us who "get" him are eternally thankful.