Rebbe Yissachar Ber of Radoshitz was accustomed every year on the 5th of Av — the yahrzeit of the Holy Ari of Tzefat— to arrange a siyum [completion] of an entire Gemara tractate, after which he would sit down with his chasidim to a festive meal of meat and wine and tell the following story:

There once lived a man whose habit it was to sleep a great deal, thereby earning him the nickname, "Sleeper." In the cool autumn mornings before the High Holidays when all the townspeople rose early for selichot, this fellow would remain asleep. So, too, on Rosh Hashanah when his wife left for synagogue, he continued slumbering.

The poor woman had to dart out of the shul again and again during the prayers...

The poor woman had to dart out of the shul again and again during the prayers to come home and try to wake her husband, but nothing helped. Finally, when the time for the Torah reading approached, she yelled at the top of her lungs: "NU! Get up! They’re blowing shofar in a few minutes!"

At this, her husband would tumble out of bed, grab at whatever feather-strewn clothes came into reach, and — still half-asleep — lurch posthaste through the streets to shul. Reaching his destination he inspired looks of astonishment and reproach from the other worshippers; the children poked fun at him.

Now all of the intense humiliation and embarrassment he suffered went up to the Heavenly Court. And when their deliberations were completed, they pronounced their judicial opinion: as a result of his degradation, this hapless fellow’s transgressions were forgiven — he was meritorious, and the case was closed.

...as a result of his degradation, this hapless fellow’s transgressions were forgiven...

When the Ohev Yisrael finished the above account, he said: "Ourselves as well: from our crushing embarrassment that in these days — when the Holy Temple was destroyed — we are nonetheless able to sit and rejoice in a festive meal, from this we merit to bring forgiveness for the whole Jewish nation."

[Adapted from "A Treasury of Chassidic Tales – Festivals"]

P.S. The Lubavitcher Rebbe used to request every year that there be a siyum every day from 1st to 9th Menachem Av, in order to bring joy into the year’s most intense period of mourning.