Jesus is about 30 years old, and ready to begin his ministry. The question is: Does he really know what he is here to do? Has he understood what his mission will be? The phrase "time will tell" isn't going to be helpful. Like a good teacher tests her pupils to learn what they know, Jesus gets a test to see what he knows about the mission.
Jesus sat down with his disciples and took the time to help them understand what prayer is and isn't, and what God is looking for. Hint: It's keeping the big picture in mind as you pray.