Heaps of Buddha
I have a pair of Birkenstocks -- you just knew I wear Birkenstocks, didn't you? -- anyway, I have a pair of Birkenstocks that I bought on my honeymoon, thirty years ago this September. Now, Birkenstocks are pretty tough, but they do wear out; I've had the Vibram soles replaced three times, the uppers eventually broke a strap so I had them replaced, and while I was doing that they rebuilt the cork part where it had worn away.
You see the joke here, of course: at this point, I've replaced all the parts, but I think they're "the same shoes". It's like the story about the farmer who bragged he had a pickaxe that was a hundred years old, handed down from his great-grandfather. Oh, he'd replaced the handle six or seven times, and he once broke the pick end trying to pull a stump so he'd had to replace the head, but the tool was a hundred years old.
This is actually a central point of Buddhism. In fact, the Heart Sutra says that Buddha became Enlightened by realizing, wholly and completely, that everything in the universe that we see and interact with, everything that is related to everything else by cause and effect, is just like my Birkenstocks: a collection of atoms that happen to be in one relationship at a particular time, but that came together from parts of other things in the past and will come apart and become something else in the future. When buddha really saw that, he saw through and recovered from the addiction of thinking there could be something permanent, and so ended the clinging to a fantasy of permanence that causes suffering.
Which is all well and good, but until we manage to Realize the Heart of Perfect Wisdom ourselves, what can we do?
That's the Fourth Great Truth: that there are upaya -- "skillful means" or "expedient means" or even "clever tricks" -- through which one can reduce one's own suffering now, and reduce the likelihood of suffering in the future. Siddhartha laid out some of these clever tricks in a program of eight steps that's usually called, in English, the Holy Eightfold Path.
I'm going to take an aside here for one of my periodic rants about the Victorian Theosophist translations Buddhism is burdened with in English. The "Holy Eightfold Path" in Sanskrit is arya-ashtanga-marga; wherever you see "Holy" or "Noble" in something in Buddhism, you can bet the original word was "arya". The problem is that arya doesn't really mean holy, and only sort of means "noble" -- it really means "valuable" or "precious". The translation to "noble" happens because the term is often used for "noblemen" or aristocrats. Chinese is more straightforward -- it's 八正道, ba1 zheng4 dao4, or "road of eight valuable things". What are these eight valuable things? They break down into three groups: wisdom, ethical behavior, and meditation.