LET'S SAY, you backed into a man holding a fragile object. The object breaks. You turn around. Thinking it's your fault, you promise him you'd compensate for it.
However, turns out, that man himself was very much aware of your back-pedalling and could have easily alerted you well beforehand, instead he continued and knocked into you as you backed into him, and thus dropped the object.
So actually, it's not really your fault after all.
Should you still have to pay for the object, plainly because you promised, even after you find out it's not your fault at all?
LET'S SAY, I promise to help deliver a package for someone, oblivious to it's contents.
And then, I find out that it's drugs that is being smuggled.
Do I comply and still deliver it simply because I promised?
LET'S SAY, you and I are strangers, seeing from afar, I see that you're about my height. I made a bet with you in which I promise to pay you a certain amount of money if you're taller than me. You agreed. We walk towards each other.
Turns out, you're taller than me.
HOWEVER, you were wearing stilts.
So you really aren't taller than me. No, you're shorter.
I still have to pay because I promised?
LET'S SAY, I promise, I will seek retribution from a certain man for the murder of someone I know.
Turns out, he is innocent.
I still kill him, because I promised, right? By the logic of 'keeping your promises'?
Basically, LET'S SAY:
1) You promise in the state of oblivion.
2) You find out the truth.
3) Do you still have to keep your promise?
Wait, let's put that in perspective once more,
LET'S SAY, you promised to get something done.
Turns out, what you have to do isn't a good deed at all.
I promised you, must I follow suit?
LET'S SAY, I thought I was wrong. I promised to make amends.
Turns out, I was not wrong, YOU were wrong.
But I promised to make amends, so I must keep my promise?
LET'S SAY, I promise, I will massacre the whole of a certain neighbourhood, on the basis that they have contracted an incurable disease that will only spread and cause a pandemic that nobody can escape from.
Turns out, they are healthy and fit as a fiddle.
But I still go on a mass genocide, simply because I promised, even if the basis is no longer true?
'Money is not the problem.' Oh really? Then why are you still seeking compensation, Mr. Hypocrite?
And I thought adults were supposedly much too mature for these games.
I'll keep my end of the bargain, but hey, that's only if Truth keeps its end of the bargain.