Nirvana, or heaven as some would call it is an interesting concept. Have you ever asked yourself to imagine such a place. For many I do believe it is described as a place of absence. A place where there is no more pain and suffering. Where there are no bosses or beggars, no credit or taxes, and certainly no worries and fears.
In the mind of another the concept may be expressed by abundance. where there is lots of money and love, children by the dozen or peace, and even wisdom and happiness.
For the purpose of this discussion I want you practice a skill we often attempt but would never admit publicly. Try your hand at assumption and try to assume what it would be like to live in a state of nirvana. After you have carefully stripped your current reality of everything that is making you unhappy, and anything that frustrate or scare you, or things that may anger you or cause self doubt, add everything that you would consider to be necessary to achieve such a state of being. Then imagine what it will be like to live such a life.
Now imagine the value of what you have gained should you never have had the things you took away. With the exception of wisdom and happines, I bet the life you have imagined loses much of the appeal that you imagined nirvana would hold. Even wisdom loses value if we find a place of total bliss.
And thus it seems there is only one quality that truly define a state of nirvana, the one called joy.