Paul said in 1 Corinthians 2:2, “I am determined to know nothing among you except Jesus Christ and Him crucified,” and in acts 26:24 it is states that Paul was a man of “great learning,” so why would he seemingly throw away his learning?
Paul realized that great learning is not the basis to Christianity, faith is. Knowledge is in opposition to faith, causing doubt. Do you remember, Jesus said the kingdom of heaven belongs to the childlike? Think of the children, at first they believe anything you say, they have faith in you. When they go to school they start to question what you say, asking why. Then as teens they choose to dismiss what you say to experience it for themselves. Knowledge destroys faith, they no longer have faith in you.
Paul learned the great lesson that Christ crucified is most important, realizing that much knowledge can be a hindrance to faith because it demands proof.
Now I am not saying that education is of no value, knowledge is of great value in that it can be used to minister to people groups that otherwise would not be reached.
Paul was able to use his great knowledge in Acts 17:16-32, speaking in Athens with the Epicurean and Stoic philosophers, who were the great thinkers of the day. Only a person of knowledge who also was a Christian could reach them for the gospel of Christ!
God has placed each of us in our sphere of influence because we have the specific knowledge to reach those around us, but in that knowledge it is important that we do not demand that God give us all the answers but rather live as a child, in faith.