A bout with gout is a reminder of the usefulness of suffering:

I know that the gratitude will not last, because gratitude can never be a chronic emotion. I will forget the pain within the week and take my painless toe for granted again. But still the episode illustrates the point that suffering is necessary for the full appreciation of life. Without some experience of it, we could hardly be aware that we were enjoying anything; and it is why it is so difficult to imagine heaven, where suffering does not and could not exist. We can all imagine, vividly, a thousand hells, but a single heaven is quite beyond our imagination to conceive. That is why the iconography of hell is varied and fascinating, that of heaven dull and boring.