Absent-minded professor!

Professor Johnson’s family was moving house. Knowing how forgetful her husband could be, his wife put a slip of paper in each of his pockets with the new address written on it. When his classes were over, all he had to do was to take out one of the slips and then drive to his new home. But during the course of the day, he uses every single piece of paper to write notes on, and then gave the notes to the students. Work over, he got into his car, it was then that he suddenly remembered that this was moving day. He could not recall at all where he was to go. But he had an inspiration. He drove to his old house, and luckily enough, there were some children playing outside. "Hi little girl!" he called to a child who was near. "Can you tell me where the Johnson’s have moved to?" "Sure, It/s just around the corner and two houses down Daddy."