You pay someone with a cheque for something, receiving a receipt for it. They do not cash in the cheque.
What is the ettiquette for this situation? Are you to go on living your life, mentally subtracting the amount of the cheque from your bank account, reserving enough money for that cheque to be perhaps paid off.
What happens after 5, 10, 25, 50 years? Can they "lose" the cheques, then come to you, asking for new ones, saying you owe it to them?
I can see within a year that you probably owe it to them, but after time goes on, it seems I personally see it as less of an obligation. It ends up being a very large hassle after awhile. Especially if the sum is large.
EDIT: as asked for in the comments, my country is Canada.