Sukkot - Are you happy?

(39) On the fifteenth day of the seventh month, when you have gathered in the fruits of the land, you shall celebrate Sukkot for seven days; the first day shall be a sacred day of rest, and the eighth day shall be a sacred day of rest.

(40) And you shall take for yourself on the first day the fruit of a beautiful tree, fronds of a palm-tree, plaited twigs of thick trees, and willows of the brook, and you shall rejoice before Hashem your G-d seven days. (41) And you shall observe the festival of Hashem for seven days in the year; it is a statute for all time in your generations; you shall keep it in the seventh month.

(42) You shall dwell in sukkos for seven days; all citizens of Israel shall dwell in sukkos; (43) in order that your generations shall know that I made the children of Israel to dwell in sukkos when I brought them out of the land of Egypt: I am Hashem your God. (44) And Moses transmitted to the children of Israel the appointed seasons of Hashem.

The four species are likened to different categories in the Jewish people.

The Esrog, which has both taste and smell, is likened to those that study Torah and do mitzvot.

The palm branch, which has taste, but no smell, is likened to those who have only Torah study.

The myrtle, which has smell but no taste, is likened to those who have only mitzvot.

The willow, which has neither taste nor smell, is likened to those who are without Torah study and without mitzvot.

(7) He used to say: The more flesh, the more worms; The more property, the more anxiety; The more wives, the more witchcraft; The more female servants, the more lewdness; The more slaves, the more robbery; [But] the more Torah, the more life; The more sitting [in the company of scholars], the more wisdom; The more counsel, the more understanding; The more charity, the more peace.