It is too easy to limit prayer to what can be.
We have the God of the Impossible. In fact, the Bible reveals a Sovereign God whose relationship with man is characterized by miracles.
It is not possible to know Him , pursue Him, worship Him, and continue to pray according to human concept.
Those who are willing to take up The Cross and follow Him will be led of the Spirit. They will pray for things they have never thought of. They will pray for things they have not heard of. They will pray for things that absolutely can not be, by human experience or knowledge.
Soldier of The Cross, there is no limit. No boundary. No request can be contrary to His Word, but prayer should be framed by the delving in to the infinite frontier of faith.
Most do not pray much.
Those who do are often limited by human perspective.
He can do anything. Anything. Anything.
He can do anything, but fail.