The most important thing during illness is to offer to God patience and thanksgiving for His merciful visitations. Sickness purifies sins and gives one time to meditate on the past.
By the death of martyrs religion has been defended, faith increased, the Church strengthened; the dead have conquered, the persecutors have been overcome. And so we celebrate the death of those of whose lives we are ignorant. So, too, David rejoiced in prophecy at the departure of his own soul, saying: 'Precious in the sight of the Lord is the death of His saints.' He esteemed death better than life. The death itself of the martyrs is the prize of their life. And again, by the death of those at variance hatred is put an end to.
But if you give a strong body rest and ease and idleness, all the passions dwelling in the soul are intensified. Then, even if the soul has a great desire for good, even the very thought of the good that is desired will be taken from you.
True joy is the joy of consolation, the joy that wells up in the knowledge of one's own weakness and the Lord's mercy, and that does not need the bared teeth of laughter to express itself.