True Regret

The Kol Mevaser explains that we can learn the meaning of true regret from Rabbi Yehudah ben Tabai's reaction when he learned that he had mistakenly sentenced a man to death. As soon as Shimon Ben Shetach explained his error, Rabbi Yehudah got up like a lion and cried out, and never forgot his terrible error for his entire life. He ran to the dead man’s grave, not once or twice, nor was he satisfied with going daily for a year or two. Every day of his life, he spent time there. He cried out there with such bitterness that they heard him throughout the city.
But this too, was not sufficient. He also took on concrete actions to ensure that he never repeat such a horrendous error. He would not rule capital cases if Shimon ben Shetach was not present. This shows genuine regret.
But of course there are many levels of regret. The rebbe of Rachmastrivka, shlit”a, once recounted the words of the Rebbe of Zlatopolia, zt”l, about how to attain tehuvah through true regret. “One should imagine he was a very wealthy businessman who was guaranteed to make a fortune provided he could transport his merchandise to a place over the seas. Instead of prudently splitting up his abundant merchandise, he sent it all along in a single ship that sank, immediately transforming him from a millionaire to a pauper.
“It is very obvious that this person will be filled with remorse for his lack of foresight and feel very foolish for risking all in one ship instead of sending part of the merchandise in one ship and the rest later on in another ship. This is how one should feel when he regrets his sins.!”