Sincere regret

Yesterday, I read a story in the Hamodia about repentance. It involved an elderly chassid who approached the Belzer Rebbe, Rav Yissachar Dov, saying that he was an old man and his time was nearly up. He wanted to know how he could repent for the sins of his youth.
"If you truly regret your sins, you will be forgiven," the Rebbe replied.
"How can I tell if I've reached the proper level of regret?" the chassid asked.
The rebbe proceeded to tell him a story about a merchant named Yankel who was on his way to a fair, having a large number of wagons with goods to be sold which were in high demand. When he arrived at the fair, it began to rain and other merchants carrying the same goods were unable to reach the city.
"Seeing the huge demands for his goods, Yankel thought he saw a way to make a handsome profit. He put off his would-be customers, refusing to sell them the goods, in the hope that this would drive the price even higher. That way, when he finally did sell, he'd make a fortune.
Yankel continued refusing to sell his goods for a number of days. The weather remained inclement and the price of his goods did skyrocket. One evening, however, the rain suddenly stopped. The following morning, the fair was filled with merchants who had arrived with their goods. Overnight, the price dropped drastically.
"When you regret your sins as much as Yankel regretted not having sold his merchandise the day before the price plummeted, the tzaddik concluded, "you may rest assured you'll be forgiven."