In The Genealogy of Morals, Friedrich Nietzsche put forward a theory of emotions which I refer to as emotional capitalism. If one of your friends or loved ones owes you a debt, and does not repay in kind, you may exact payment by being mean and nasty to them. If you owe them a debt, you can repay by being nice to them, or by letting them be mean to you. If someone owes you, you may seek their feelings and expressions of gratitude to pay the debt, or inflict emotional pain to recover your debt. Emotional capital is the debts and credits you owe, or are perceived to owe, to the people in your life.
Emotions can be explained in this way: you feel guilt if you owe a debt to someone else to give them your pain in order to pay off your debt. You feel shame if you owe a debt for failing social norms or if you owe a debt to society, again, to give your suffering to your creditor as payment. And you feel anger toward someone if they owe you a debt which they are not repaying, to extract what you owe from them by getting pain from them when you cause pain to them.
This theory takes its most interesting turn with the idea that, when you owe something to yourself and fail to obtain it, you owe to yourself a debt you cannot repay, which you must then pay to yourself by inflicting pain and punishment upon yourself: this is the theory of emotional guilt. Later it will become clear that shame usually causes guilt to go with it, because you let yourself down by not being good enough for the others whom you sought to impress, and, for this reason, guilt and shame can function as one entity in reality.
From here we finally see the groundwork laid for a theory of moral bankruptcy. In legal bankruptcy, the law forces creditors to absolve the debts of the debtor, in order to give the debtor a fresh start and freedom. Absent bankruptcy it would probably be inevitable to bring back debtors prison and indentured servitude, which is a road to slavery. Moral bankruptcy operates along similar principles. Michel Foucault once hypothesized that there is an Internalized Other in each person's head whereby society conditions a person to cast society's judgment upon himself internally. To the extent that a person has a sense of social judgment, and an accounting of one's emotional capital, one acts in this capacity as bankruptcy court judge, and one then looks in the mirror and sees oneself as debtor to oneself as creditor, to the extent one failed in what one was morally obligated to give to oneself.
You were stupid in how you applied for a job, you did not try hard enough to obtain a goal, you did not put up enough of a fight to save a romance, etc. You look at yourself and declare that you are filing for moral bankruptcy. The judge then absolves all emotional debts, you are forgiven, you have absolved yourself for the sin against yourself that you had committed, and you move on with your life.
The definition of emotional maturity is explained by the theory of emotional capitalism. It is the constant forgiveness of small debts to other people in your life who have been good to you in the past. Someone annoys you with some small wrongdoing against you and you forgive them instead of seeking to recover what they now owe to you, and you forgive them in your emotions, and hold no urge nor feeling to get pain from them.