But it is not so. Simchas Torah, which begins anew the yearly cycle of reading the Torah, is a Yom Tov. This shows us that the Torah extends through the physical realm and beyond. Torah is the source of all creation and life, existing forever. So if one understands that the eighth day, Simchas Torah, gives meaning and life to the other seven days, then one rejoices.
True joy comes when one discovers the real meaning of life.
One of fear and awe, and one of love, joy and happiness. Some mitzvos lead us to Hashem through fear, and others through joy. Come holiday time, we have a healthy dose of both. On Yom Kippur we afflict ourselves with fasting and supplications, to clarify for ourselves the awesomeness of He who created us, and the dread of His impending judgment. On Succos, we sing, dance and eat festive meals outside in the succah, and enjoy the blessings of the new year.