Kol Nidrei.

All vows, renunciations, promises, obligations, oaths, taken from this Day of Atonement till the next, may we attain it in peace, we regret them in advance. May we be absolved of them, may we be released from them, may they be null and void and of no effect. May they not be binding upon us. Such vows shall not be considered vows; such renunciations, no renunciations; and such oaths, no oaths. (Translation adapted from the High Holyday Prayer Book, edited by Rabbi Ben Zion Bokser.)

This is an interesting article on the Kol Nidrei prayer, which is chanted in synagogues on the eve of Yom Kippur.  Apparently, the gist of the prayer is the nullification of vows, either vows taken in the prior years or in the next, but not vows to one's fellow man.  The article is pretty obscure on that point.  Here's a part of the article:

The language of Kol Nidrei, chanted in Jewish congregations just before Yom Kippur, is complex, obscure, and legalistic. Yet it continues to fascinate. Rabbi Lawrence A. Hoffman, professor of liturgy at Hebrew Union College-Jewish Institute of Religion, has edited a new collection of essays titled All These Vows: Kol Nidre. Those who want to prepare for Yom Kippur by understanding the reasons for the lasting fascination with Kol Nidrei should read the first half of this book—but may want to stop before the second half.


No one knows for sure how Kol Nidrei originated. It is by far the best-known Yom Kippur prayer, but in fact it is neither a prayer nor actually recited on Yom Kippur. Rabbis have never liked it. In the early Middle Ages, some of them sought to exclude it from the liturgy altogether. Others, a few centuries later in France, changed the wording to render it more palatable. Still others, in 19th-century Central Europe, excised even the newer version from the liturgy. Yet its melody evokes Jewish associations so intimate that even many who are otherwise completely estranged attend synagogue to listen. The tune was appropriated by Beethoven and popularized by Perry Como and Johnny Mathis. Al Jolson sang it at the emotional climax of the film The Jazz Singer, the first full-length talkie, in 1927.


One of the great mysteries of Jewish liturgy is how Kol Nidrei achieved its exalted role on Yom Kippur eve, the holiest day of the Jewish year. The text, devoid of emotional resonance, is a technical legal formula that nullifies vows. Since halakhah prohibits nullification on Sabbaths and holidays, Kol Nidrei is recited before the onset of Yom Kippur. In its original form, still used in the Sephardic rite, it refers to all vows taken over the course of the previous year. The formula does not actually conform to talmudic requirements for nullification: For one thing, there is no mention of any specific vow that needs undoing. Therefore, rabbis in the 9th and 10th centuries discouraged its recitation. But rabbinic opposition could not overcome what, by then, had apparently become a deeply-rooted folk practice. In the early 12th century, Rabbi Jacob Tam, grandson of the great talmudist Rashi, sought to ameliorate halakhic objections by changing the wording so that it referred not to vows already made but to those that would be taken in the coming year. This became the predominant version among Ashkenazim.

In Jewish law, the nullification of vows does not apply to obligations undertaken toward one's fellow man. Nevertheless, anti-Semites had a field day with Kol Nidrei, because the prayer's formula reinforced the notion that Jews were authorized by their religion to renege on promises and that they could not be trusted. As a result, medieval European tribunals demanded that Jews take an especially humiliating oath, designed to counteract what was understood as Kol Nidrei's dispensation to break their word. With the emancipation of European Jewry that began in the late 18th century, and the possibility of acceptance as equal citizens, Kol Nidrei was seen as an embarrassment. The Reform movement went so far as to eliminate the prayer from its liturgy in 1844.

A Commentary article from 1968 explains further:

The vow (neder) is one of the earliest forms of prayer known to Scripture, but a growing religious sophistication over the centuries led to a downgrading of this primitive form of prayer. The Pharisees, for example, took a dim view of candidates for their fellowship who were prone to the making of vows. Indeed, the Torah itself discourages vowing: “When you make a vow to the Lord your God, do not put off fulfilling it, for the Lord your God will require it of you, and you will have incurred guilt; whereas you incur no guilt if you refrain from vowing” (Deuteronomy 23:21-23). The Torah further provides for the annulment of certain vows, notably those made by females who are legally within the jurisdiction of their father or husband (Numbers 30). And Scripture, generally, cautions against vows lightly taken: “Be not rash with your mouth, and let not your heart be hasty to utter a word before God . . . better it is that you should not vow, than that you should vow and not pay. Allow not your mouth to bring your flesh to guilt . . . but fear God” (Ecclesiastes 5:1,4,6).


The post-biblical moralists shared this attitude and tried to dissuade Jews from resorting to vows as a demonstration of piety. In the period of the Mishnah, the habit of making vows was held to be a mark of low breeding. Some of the rabbis permitted the use of vows as a means of reinforcing resolutions to replace bad habits with good ones, but others disapproved. A favorite Talmudic maxim says, “It is sufficient for you [to limit yourself] to that which the Torah forbids.” In third-century Babylonia, the distinguished Amora Samuel derogated those who, like the Nazarite, adopted vows of abstinence: “Even though he fulfills [the vow], he is called wicked.” The Palestinian authorities were inclined to be more indulgent than their Babylonian colleagues in the matter of vowing; yet it was a Palestinian Tanna, Rabbi Nathan, who said: “One who vows is as though he built a high place, and he who fulfills it as though he sacrificed thereon.”

Despite such injunctions, not every Jew could resist the habits of centuries of Oriental vow-making. Thus the legal authorities in the Talmudic period had to cope with the dilemma of preserving the sanctity of the pledged word in a society that continued to make ill-considered vows. The problems—legal and moral—which perplexed the most eminent rabbis in the matter of the dispensation of the many types of vows, oaths, etc., are so complex and subtle that it is impossible to discuss them here in detail. Two entire tractates of the Talmud (Nedarim and Shevuot) deal directly with these issues, to say nothing of discussions in other tractates.

We can see a similar sentiment in Jesus' edict that we should let our "yes" be "yes" and our "no" be "no."
There seems to be a basic human need to be released from self-imposed obligations.  We can see that in confession, but also in the Kol Nidrei prayer.

And Happy Hanukkah to you, Dennis.

Dennis Prager recounts his trip to Morocco when he was 20 and discovered that although he was a practicing orthodox Jew, he missed Christmas, and, therefore, America.

When I was 20, I spent my junior year in college in England. When classes let out for the last two weeks of December, I traveled to Morocco, where something life-changing occurred.


What happened was that I felt a longing, even an emptiness, I had never before experienced. Something was missing from my life, but I could not at first identify it. I knew it was not about being without friends or family — after all, I hadn’t been with family or friends in England for the previous three months. And it wasn’t about being alone — I had gotten used to traveling by myself.

This sense of missing something kept gnawing at me, until one day I realized what it was: I missed the Christmas season. I missed that time of year in America.

And:

I came to two life-changing realizations. First, though my yeshiva world did everything possible to deny the existence of Christmas — for example, we had school on Christmas Day, and “midwinter vacation,” as it was called, was at the end of January, not at the end of December — this yeshiva boy really liked the Christmas season.


And, second, this Jew, whose yeshiva upbringing taught him to think of himself only as a Jew, was in fact an American as well.

Though it took more than a few years to fully realize just how deeply American I was and how much I appreciated American Christianity, it was Christmas in Morocco in 1968 that first opened my eyes. And I was never the same.