Concerning this, those who speak in parables say "Come to Heshbon...." [Chukat 21:27]
In Maseches Bava Basra [78b], Chazal expound on this verse as follows: "Regarding this hamoshlim would say - This refers to those who rule [hamoshlim] over their yetzer hara. 'Come to Cheshbon' - Come and let us make a calculation [cheshbon] of world importance." This teaches us that it is incumbent upon each individual to evaluate his deeds in order to determine whether or not he is acting properly.
R' Yitzchak Blaser, one of the primary figures in the Mussar movement, was approached by members of his community who requested that the Rav rouse them with words of inspiration in light of the upcoming High Holy days.
"Allow me to draw a parable" he began. "A caravan lost its way in a forest. For a week the travelers wandered around aimlessly, unable to find their way out. Suddenly, the men saw a lone figure walking in the distance. They quickly made their way toward him and asked him to show them the way out of the forest.
"My brothers and friends" replied the man, "you have been roaming this forest for only a week. I, however, have already been lost for several weeks. Let us try to find the way out of here together, perhaps then we will be successful."
"But there is one area in which I can be of assistance" continued the man. "I will tell you the paths that I have already tried, and we will know not to mistakenly tread them again."
"This applies to our own situation as well" said R' Blaser with great humility. "I am just as lost as you are; only more so, for I am old and have already been lost for many years. Yet my experience can be of benefit, as I will be able to enlighten you as to things that I have seen in my life which I have investigated and found to be trivial and meaningless!
"You can trust me on those matters that it would not be worth your while to try those things.
"Come, let us search together for the path that leads to complete repentance!"
Source: Rabbi Yisrael Bronstein