Every yom tov has its own unique character. Regarding the holiday of Sukkos there appears to be a basic contradiction between two conflicting themes. On the one hand, the Maharil explains the reason that Sukkos comes following Yom Kippur is that if it was decreed that an individual or community go into golus - exile, as result of the judgment of Yom Kippur, they can serve this sentence by exiting their homes for a seven day period, and reside in a temporary abode, the sukkah. This teaching is found earlier in the medrash Yalkut Shimoni, (Vayikra 653), in the name of Rebbe Eliezer bar Marnus, that if the Jewish nation were judged to be exiled, their going into their Sukkos, is considered On High as if they went to Bavel.
Moreover, this concept of uprooting oneself and moving into a temporary dwelling as found in halacha. The Talmud (Sukkah 8b) teaches that if one lives in a kosher sukkah all year long, they cannot fulfill their mitzvah of sukkah by remaining in that sukkah, but must leave their permanent sukkah and like all Israel, experience the phenomena of relocation and enter another sukkah. This is codified in Orach Chaim (636:2). It is not sufficient that one resides in a kosher sukkah; one has to experience literally the move.
Yet, paradoxically, we find that Sukkos is defined as a most happy, joyous festive holiday. The Yalkut (654) notes that the charge to be in a state of simcha - happiness is found three times in the torah regarding the yom tov of Sukkos. Interestingly, regarding Pesach there is no biblical directive for simcha, and the holiday of Shavuos has simcha incorporated but once. The Zohar (Parshas Emor) ascribes some of the special simcha of Sukkos, to the seven ushpizin - privileged guests who join us daily in the sukkah. What is perhaps most fascinating is the exception to the rule that exists regarding the mitzvah of sukkah, namely that mitztaer - one who is uncomfortable and pained by fulfilling the mitzvah of residing in the sukkah - is exempt thereof. Regarding the observance of Jewish law we are generally governed by (Avos 5:26) lefum tzarah agrah, i.e. the reward is in proportion to the difficulty and exertion. If one does not enjoy eating matzah, or when we had, and please G-d in the future will have, the korban Pesach, their lack of enjoyment is not an exemption. The Yerushalmi relates how some rabbis endured a headache from Pesach to Shavuos as a result of drinking wine and not grape juice for the mitzvah of daled kosos. Sitting in the sukkah is radically different. If one is troubled by extreme weather conditions under which they would not remain even in their own home, or if they are troubled by unpleasant odors or disturbing insects, the Shulchan Aruch (Orach Chaim 640:4) rules that they are exempt from the sukkah [except the first night that even under those conditions one is to eat a kezayis in the sukkah].
At first glance there appears to be a startling inconsistency whereby exile and leaving one's comfortable home usually denotes hardships and sufferings bereft of the conveniences of home. Yet in the sukkah we are mandated to merge these divergent motifs.
The Torah (Vayikra 23:43) teaches that we are to reside in Sukkos "L'ma'an yeid'uh doroseichem ki ba'sukkos hoshafti es Bnai Yisroel b'hotzi'ih osam mei'Eretz Mitzrayim - so that your generations will know that I caused the Children of Israel to dwell in booths when I took them from the land of Egypt". Rav Yosef Salant zt"l, in his Bear Yosef, notes that we are told to relive and reenact, not simply remember the manner in which Hashem provided for us in our forty year trek through the dessert. The annei haKovod - Clouds of Glory provided millions of travelers in the dessert with perfect climate control - air conditioning by day to protect them from the beating sun, and heat by night to dispel the chill. Moreover, these clouds worked overtime at night by providing fresh laundering and dry cleaning for their clothes. They were provided miraculously with manna from heaven satisfying their individual tastes and diets, and fresh drinking water was supplied in abundance despite their location being far from any oasis. In their travels and exile from Egypt to the land of Israel, Hashem provided them with all the comforts of home. It is for this reason, explains the Bear Yosef, that if one is mitztaer - uncomfortable in the sukkah, that they are exempt thereof as this would negate the positive characteristic of sukkah of reliving His abundant kindnesses. This understanding of our stay in the desert, after which our mitzvas sukkah is modeled, puts to rest the sukkah paradox: through the mitzvah of sukkah we reenact our desert experience, which included being in a form of galus but also included Hashem's infinite kindness in making that galus very comfortable.