Sometimes we get to a certain level of knowledge and think that "we have arrived!" Ever been there? We don't want to hear anything more about it ... we have already learned it all! The minute we begin to think this way, we are setting up the stage to backslide.
1 Samuel 15:23 says that this is an act of rebellion which God calls "witchcraft". He is a progressive God. There's nothing wrong with hearing again something you've heard before ... usually this review will open up more things in the same verses.
Maybe we have learned it all ... maybe we haven't. There's always more that we can learn; God's Word is inexhaustable.
Reverend Robert W. & Mary C. Butler