Because of my Calvinistic upbringing, I was trained to think that what you do has to have a purpose.
A 'No' uttered from the deepest conviction is better than a 'Yes' merely uttered to please, or worse, to avoid trouble.
I found in one of the tombs an inscription saying, 'If you touch my tomb, you will be eaten by a crocodile and hippopotamus.' It doesn't mean the hippo will eat you, it means the person really wanted his tomb to be protected.