We need to learn to praise the Lord as much for a closed door as we do an open door. The reason God closes doors is because He has not prepared anything over there for us. If he didn't close the wrong door, we would never find the right door.
God directs our path through the closing and opening of doors. Once a door closes, it forces you to change your course. Another door closes, it forces you to change your course again. Then, finally, you find the open door and you walk right into your blessing.
Knock and It Shall Be Opened Unto You
My hope for you is that you find your blessing behind the door you come upon along your journey in life.