In modern society, a person would not appear in court (even small claims court), without preparing his or her case, so as to be able to present it to the judge in the most convincing fashion.
Thus, Kal Vachomer [a Talmudic term meaning "certainly"] a person should not come into Rosh HaShanah without properly preparing their case for presentation before the Heavenly court.
Hence the month of Elul - an annual opportunity for self-examination and preparation for judgment.
Raba (an Amorah or late era Talmudic sage) says in the Talmud (Tractate Shabbat page 31A) that among the first questions to be asked of a human being upon Final Judgment are the following:
Did you conduct your business dealings with integrity?
Did you set aside fixed times for the study of Torah?
Did you concern yourself with the duty of raising a family?
Did you retain a confident faith in Israel's future redemption and the coming era of universal peace?
These are questions that a person should not wait to be asked until death. Rather, one should ask these questions on a daily basis and especially during Elul, thus reminding oneself what the most important priorities in life should be.