Rick Riordan has written a series of novels for teens called Percy Jackson and the Olympians. The premise of the books is that all of the Greek gods from mythology are real, as well as all of the monsters and half-human offspring of the gods. These being are all supposedly still active in the modern world. The reason normal people don't notice all of these creatures from mythology and these explosive events happening all around them is that mortals' minds are blinded by "the mist." It is a force which causes human beings only to see what they think they should see and prevents them from seeing things that don't fit their preconceived notion of reality, like Cyclopes or centaurs or giant manticores. Obviously, this idea that human beings tend not to see anything beyond what fits their preconceived notion of the world is integral to the books.
Part of what allows the reader to suspend disbelief and accept "the mist" as believable is that we know human beings act like this all the time. Every day we encounter people (and sometimes are people) who miss the obvious because it doesn't fit with our notions of reality. We can even see this tendency in Jesus' disciples. In Matthew 16 Jesus begins to describe to his disciples what is going to happen to him in the days leading up to his crucifixion, that he "must go to Jerusalem and suffer many things from the elders, chief priests, and scribes, be killed, and be raised the third day" (Matthew 16:21, HCSB). But then Peter takes Jesus aside and begins to set Jesus straight. "Oh no, Lord! This will never happen to you!" (verse 22, HSCB).
For Peter and the other disciples who had finally come to believe that Jesus was the Messiah, the idea that Jesus would suffer and die was inconceivable. In general, the Jews of the day had come to believe that the Messiah would be a conquering king who would sweep the Romans out of Jerusalem and then out of Judea and would restore Israel to its rightful place as the dominant power in the world. Suffering and dying did not fit their idea of the Messiah and so they refused to believe it. Can you imagine, walking up to the man that you have just acknowledged to be the son of God (Matthew 16:16) and telling him that he is wrong?! But Peter did exactly that because what Jesus had in store did not fit his preconceived ideas of what the Messiah was supposed to be.
How often do we do the very same thing? How often do we miss out on what God has in store for us because we are so full of our own ideas of how things are supposed to work that we miss the obvious? Sometimes, we get it in our heads that God only works a certain way, even when, like Peter, Jesus is stating in fairly clear terms that something else is going on. We decide that a particular person is a lost cause when Jesus is saying, "That man will draw the world to me." God allows us to go through difficulty in order to stretch us and teach us but we are so convinced of our own maturity that we miss the lesson entirely.
Today, instead of walking around, making assumptions about how the world works or about the ways God "always" does things, step back and try not to take anything for granted. Try to remember that our expectations can sometimes be way off and let God do what God wants to do. Let's learn from Peter's mistake and not try to convince God that God's plans are wrong.