If Not Now, When?

Chazal exhort us to take advantage of the special accessibility to Hashem afforded us leading up to and during the aseres yimei teshuvah. Rav Chaim Brisker, zt”l, once explained this idea with a parable:
There was once a Polish town that lay close to the Russian border. Because of the constant skirmishes between the two countries, the border shifted several times. At one point, the border intervened between the town and its Jewish cemetery, and this caused great problems for the Jews. Every burial meant undergoing interrogation and cross-examination by the intransigent border guard.
The Jews appealed to the authorities, and managed to reach an agreement so that funeral processions would not be stopped as they crossed the border and the Jews could bury their dead without the indignity of delay. Some enterprising locals soon realized that this was a golden opportunity to smuggle contraband across the border. They dressed up as Jews, filled a coffin with illegal goods, and successfully carried it across. Delighted with their plan, they repeated it several times over the succeeding weeks.
One night, the border guard heard the merry sound of singing and laughing. Looking out from his hut, he spotted a group of “Jews” carrying a coffin towards the border. Suspicious, he stopped them and asked to see inside the coffin. The “Jews” refused to open it, saying, “Don’t we have an agreement that Jewish burial parties may pass?” The guard insisted, and discovered the contraband. Well aware of the deep trouble they had gotten themselves into, the smugglers all fell to their knees and began crying and pleading for mercy.
“Fools!” said the guard. “Had you cried before, you wouldn’t have to cry before me now!”
“Similarly,” concluded Rav Chaim, “When trouble descends on people in the middle of the year they cry and plead with Hashem. They don't realize that if they had cried during the auspicious time of Elul, and especially during the yomim noraim and aseres yimei teshuvah, they would not have had these troubles to begin with!”