Sukkot marks the beginning of the rainy season, and Rabbi Eliezer opines that we should start saying masheev haruach umoreed hageshem starting the first day of Sukkot. While Rabbi Yehoshua does not disagree that, in theory, Sukkot is the correct starting point, "since rain on Sukkot is a sign of a curse", he ruled that we should push off the recital of masheev haruach until Shemini Azeret—which is the practice we follow today.
We generally tend to view exile from the land of Israel as punishment for our sins, an apparent truism reinforced during the Yom Tov mussaf that begins, "because of our sins, we were exiled from the land".
The Gemara (Pesachim 68b) records a debate as to the proper way to celebrate Yom Tov. Rabbi Eliezer says that one must make a choice; we must either “eat and drink, or sit and learn”, whereas Rabbi Yehoshua says, “Divide it—half for eating and drinking, and half for the beit midrash”. Rav Yochanan (living three generations later) explains that this argument is actually rooted in contradictory Biblical texts.
As more and more of our economy runs on credit, as we increasingly pay for purchases with debit cards or even smartphones, the necessity—or even the capability—of using cash is becoming less and less common.
Truth be told, this not a modern phenomenon. “Rabbi Yochanan said: According to the words of the Torah, money acquirers ownership; yet why was it said that one must lift an object [in order to acquire ownership]? It is a [rabbinic] decree, lest he tell him, ‘Your wheat was burned in the attic’” (Eiruvin 81b).