Reckon up......................

27.  Do not indulge in dreams of having what you have not, but reckon up the chief of the blessings you do possess, and then thankfully remember how you would crave for them if they were not yours.  At the same time, however, beware lest delight in them leads you to cherish them so dearly that their loss would destroy your peace of mind.

-Marcus Aurelius,  Meditations, from Book Seven