During Kol Nidre, which ushers in Yom Kippur each year, the Jewish community does something seemingly odd. We publicly declare all of our vows between a person and God null and void from this Yom Kippur to the next one. Rabbi J. B. Soloveitchik points out that we nullify vows based on two premises (explained in Shulchan Aruch Yoreh Deah 228).
1. At the time a promise was made, a person was ignorant of some circumstance that made it too difficult to perform the promise.
2. At the time of the vow, the person was not ignorant, but came to regret the promise as time moved on because of new circumstances. Fulfilling the vow became too difficult.
Kol Nidre makes these assumptions with its grand stroke of remitting a statement that all these vows disappear for the next year. This future thinking makes us more attuned to our future vows, cautioning us against making regrettable promises.