If I owe you a pound, I have a problem; but if I owe you a million, the problem is yours
A debt is something that you owe, and this can refer to a financial debt or to some other type of obligation instead. If someone saves your life then you are indebted to them and owe them your gratitude. If you have committed a crime then your debt is to society, and this is paid by completing the sentence that you were given by the courts.
If I owe you a pound, I have a problem; but if I owe you a million, the problem is yours
Debts are nowadays like children begot with pleasure, but brought forth in pain
Never in the field of human conflict was so much owed by so many to so few
Some debts are fun when you are acquiring them, but none are fun when you set about retiring them