Only B’simcha Simchas Torah

“For everything there is a time.”

Simchas Torah comes out immediately after Succos. The reading of the Torah has always been completed at the end of this yom tov, going back all the way to the time of Chazal. In fact, there were communities in which the Torah was completed only once in three years, and even they finished the reading on Shmini Atzeres. Apparently, this is the time meant for completing the Torah, perhaps because at the end of the cycle of the yamim tovim (Rosh Hashanna, Yom Kipur, Succos, Shimi Atzres) we reach a climax which is ripe for a siyum on the Torah.