Think about all the things that worry you. If you want 100% peace of mind, how much would each contribute to that if they went away?
So & So owes you money. How much would that going away contribute to your peace of mind? 5%? Then it’s trivial, not worth putting effort into — forget about it. 15%? OK, that’s significant. Let it go so you can have that 15% peace of mind back. It’s worth letting go…