I guess so it is with Jesus who said many things and he really didn't know what registered and what didn't register in the minds of people. The Gospel today says, "with many such parables he spoke the word to them as they were able to understand it."
There is a line in today's Gospel though which suggests that Jesus processed his disciples' understanding of his teaching. The line reads: "to his own disciples he explained everything in private."
When I read this line, I couldn't help but think that the disciples were the first Christian prayer group with Jesus himself as its guide. Through this private explanation, Jesus could check how his disciples understood his teaching, what registered with them, and further expound on what he meant.
And I guess such intensive formation was necessary because these folks would be expected to carry the ball after Jesus ascended.