Why Don't the Disciples Ever Seem to Understand Much?

i think if you look across the gospels, this problem of the disciple's incomprehension is especially pointed in mark. Ah, and i tried to do some of the cognitive devotion, living it out thing. And i think you finaly, like bridged it in a way that fully makes it coherent to us. But why don't you think in john that the disciples seem to understand much? Although john, they get a better shake than most, most gospels.