Why do you think the disciple John was given so much infinite and intimate knowledge of Jesus Christ?

He's called the Apostle of love for a reason. Maybe God knows that in his heart, he loved Christ the most. He loved Christ enough to be at the Crucifixion, where the other Apostles were afraid to go. Because of that love, he was given responsibility to take care of the Virgin Mary. He is the Apostle of love. Good question, Birdy.