chasing your tail

Why do we pray for our wills to line up with God's, our desires to be the desires of God, but when our prayer is answered, we believe our desires can't possibly be those of God, and keep praying the same prayer?
For some reason, we've been brainwashed with a theology that says that our desires are so far from God's that we continually have to sacrifice them so that we can follow him in obedience to what he desires for us. The problem is that when, in obedience, we share his desire, we recognize it as our own and cast it sacrificially aside. Where is the theology that God can instill in us a desire for what he wants to prepare us for? It's what we're praying for.
We can't shake the feeling that anything we desire is out of line with him, even if he intilled that desire in us.
Based on the contexts of students who have come through my office, I have to imagine that there are plenty of people who, feeling that God wanted them to heal people, have given up being a physician to follow him in obedience.