Parables were a common form of teaching in Judaism. As we see in the parables that Jesus taught, parables were usually in the form of stories that had two meanings. They were analogies, for hidden meanings.
In Isaiah 6:9-10 first mentioned that this same verse was God's way of hiding the truth from unreceptive people. Jesus taught in parables for the same reason. While His stories were entertaining, and made sense to everyone, their true meaning could be discerned only by believer's.
It is somewhat surprising that Jesus had to explain the meaning of a couple of parables to the apostles. As Jesus explained to them, when He talked in private to them about the sower, when you understand the parable of the sower, you can understand all of the parables.
Jesus did not decide who would understand or not. He spoke words that believers understood, and nonbelievers didn't. It was said in some commentaries that Jesus showed unbelievers mercy, by not exposing them to more truth which could increase their condemnation. It kept them in the darkness they love, since they rejected Jesus.
You might want to read a few parables with the idea of trying to see yourself in each one. I did, and I got a chance to see myself in more than one of them. Besides being serious, it was actually an eye opener to the way I am. Have a blessed day.
Praise the Lord!
Remember Jesus Loves You
Prayer of Salvation
Lord Jesus, I thank you for what you did on the cross for me. Your blood washed away all my sins, by your stripes I was healed, your death and resurrection brought me salvation. Please forgive my sins, and come into my heart as my personal Savior.
Thank You Lord