The disciples had to learn, often the hard way, that following Jesus does not mean favoritism from Him. They had to learn that service towards God and others is to be done with a loving, gracious attitude and not with an ego.
You have to admit that James and John thought a lot about their ability to serve the Lord Jesus. They wanted places of honor in the Kingdom of God without coming to grips with the hardship that follows everyone who gives their lives to Him. The disciples and all who would surrender their lives