The above verse is an example of true godly repentance of sin. Jesus speaks of how much is forgiven. The "much" is in reference to the weight of sin which can mean a particular sin and the amount of sin. Whether it is true or not some see their own sin as being worse than others and sometimes more than others. Jesus makes a reference to the amount of debt that is due. The debt being analogous of sin. This is never made more clear than in Romans 6:23 which tells us that our sin is a debt to God. The main idea in Jesus story is that those who realize their sinful state and just how much debt (sin) they owe God (sinned against God) are the ones who love and appreciate God as they should. Those who do not ( much like the pharisees) have no real understanding of what God has done for them and cannot love Him. We cannot come to God, through the cross and Christ, and not deal with our sin. We cannot come to the cross and not feel the weight of our sin. We cannot come to the cross and not feel the shame of our sin. Who has come to the cross, has dealt with their sin can now move forward without repentance of that same sin. It is not possible.