"Griefs, at the moment when they change into ideas, lose some of their power to injure our heart." - M. Proust
While we are more than able to use our minds without being in pain, it is my experience that we become most inquisitive when distressed. We suffer, and we consider this pain carefully, so as to place the it in context. It helps to understand its origins, plot its dimensions, and reconcile ourselves to its presence.
One might argue, and some have, that reading Proust's opus "In Search of Lost Time" is itself painfully difficult. Hence it would stand to reason that the story has a lot to teach us.
One of these lessons is how to suffer successfully and to learn from our pain - something I have found quite inspirational of late. Ignorance may be blissful, but it is when we engage with our grief, we have the incentive to confront difficult truths.
Suffering it seems opens up the possibilities for intelligent, imaginative inquiry...and Proust might make the point that reoccurring misery develops a heartier more workable approach for life. Something more attainable than a utopian quest for the perfect and happy life.