Maybe heaven is having both the freedom and the will to do that thing which your soul craves; the thing that crouches, like a word on the tip of your tongue; surges, like the ocean swell; fights, like a dog against a chain. Desire for it can be restrained but never vanquished. You neglect it for the sake of duty or for lack of time or out of fear, but it is the one thing you know is true, without doubt or demonstration.
It approaches each of us differently, and as a result we are forever misnaming it. It is Truth, but goes far beyond any account of the facts; It is Beauty, but is immaterial and unadorned; It is Love, but it is impartial. It is the wedding of what you long to be with that which you long to do; of what you desire to give with that which you desire to receive. Heaven is to act without self-thought and yet be satisfied; to abandon all else for the sake of one passion, and find that it is the road to everyone and everything else. It is exactly what you were made for.
We could call this passion, "God", and say that we find final purpose in "worship of God", and that would be true, though perhaps misleading. This suggests a uniform human experience of it, and leads us to think we may lose ourselves in God, as masses before a powerful orator, or a man before the muse. When you throw yourself into God, you journey from the collective to the individual, from the vague to the specific, not the other way around. God has specially named each one of us, and heaven will be, at last, finding out that name.