Example: Suppose a wife, totally in love with her husband, had two options: 1) life the rest of her life happily married and blissfully ignorant of his transgression or 2) know the truth and never get married again. If you ASKED her if she would want to know the truth she'd say yes. And if she found out the truth, she'd never say "i wish i never knew and he just kept on cheating on me behind my back". But she would have been happier if she had not known. Its an interesting situation reallyh.
Your example, simon17, is certainly appropriate within the context of the OP. It's rather sad, actually, because delusion is nothing like truth and it is only truth that will set you free. I once asked my wife the question "If the WTS is not what it represents itself to be, would you want to know?" and she was unable to answer. She just kind of shrugged, said nothing and averted her gaze. I took that to mean "no". So, maybe the wife in your example, if she was to really think about it, would not want to know the truth if proffered evidence that her cherished and trusted husband was in reality a philanderer. Would she be better off knowing the truth? If the cost is whatever love she gets from her cheating husband is forever lost and not replaced by love from another, perhaps not. But what a sad situation that would be, to be enslaved for life to a lie. It would be better, in my estimation, to be freed by truth and then seek out someone who will be true to you, even if in the end the search is fruitless.