Every time I read this verse I think of pastors who spend the majority of their ministry parked in the OT. Who try to explain even the most minute words by defining them in Greek or Hebrew. The NT is revealed to us through the Holy Spirit. Not based on knowledge.
Paul was a very educated man but could not see the glory of God through all of his education. Grace had to be revealed to him by the Lord. Paul was willing to forfeit all for the knowledge of Jesus.