Question:

Can you explain why laws never seem to revert back to their original form? For example, some holidays are two days outside of Israel because of the difficulty with keeping time hundreds of years ago, which has since been resolved.

Answer:

Simply put, customs have the import of law since the Torah itself recognizes them as law. That makes sense, because the basis of Torah is not the book, but the people. How do we know the Torah is true? Because the people witnessed it, accepted it and passed down the tradition. So without tradition, we have no Torah.

But there's more to it than that. Really, your question gets down to a core issue about Torah. What is the Torah, a book or a wisdom?

If the Torah were a book, then there would be "the real Torah" as it is written in the book, and "the dressed-up-with-customs Torah." Every once in a while, we might take off one set of dress-up and replace it with another—or do without it altogether. In other words, there would be the essential Torah-by-the-book and a disposable, optional set of customs.

But Torah is not a book, it is a Divine wisdom that enters into the world through the collective Jewish experience. What was written in a book some 3300 years ago is the wrapped-up Torah, like a seed containing the DNA for all the future. The Jewish People are the earth in which that seed was planted. And G‑d is the gardener. The difference being that a gardener never really knows how his plantings will grow, but this Gardener had everything in mind to begin with (being, as He is, beyond past and future). He plants the seed that contains everything packed tightly into nuances, codes and anomalies, and watches His wisdom unfold in history and tradition.

So when the Jewish collective consensus, including the learned rabbis, the wise grandmothers, the nursing mothers and the working men, all accept upon themselves a tradition that arises out of our understanding of the Torah, G‑d, so to speak, snaps His holy fingers and remarks, "Success! They got it!"

Now the answer to your question becomes obvious: How could we throw away G‑d's success?