Overdue fees ...

If you rent, borrow, or use something that's not yours, there is potential for you to return it later then you should.

For example, here in the NY Public Library, they have a wide selection of movies but if you keep them beyond their due date, you'll be dinged 3 dollars. So what was once free is now infinitely more expensive.

If you borrow, rent, or use something that is not yours, upon rental, put a reminder in your phone, day planner or email that will notify you in advance of it's due date so that you can enjoy your borrowed goods to their fullest and still return them to their rightful owner.

Late fees add up, don't think they don't.

But if you find yourself the recipient of a late fee, make sure when you pay it, you get a receipt acknowledging closure of that debt. I've heard of people paying their library fines (up to 8 or 10 dollars) not getting a receipt, only to find out payment wasn't recorded. Boo.

In short: Return things on time. But if you don't and you have to pay a fine, get a receipt. Everybody wins. The lending body gets theirs and you get record of your payment.