So he locked himself in his study for over 3 years? If you mean his life application and knowledge of Christ and His Word, I agree...and believe that is the same approach that should be taken today.
Go back to the sermon on the Day of Pentecost.
First, they were told to wait there. While waiting Peter had plenty of time to pray and spend time in God's Word.
In the first part of chapter one we find 120 disciples all praying together.
Then the Day of Pentecost "fully came," and they were all filled with the Spirit. Peter preached. Note in Peter's sermon that he had no trouble, without notes, making exact quotes from Joel 2:28ff, quoting Psalm 110, and other OT references. His message was full of OT quotations. He didn't have any written notes; his tablet or I-pad; or even a NT for that matter. But his message was filled with Scripture and the application of it.
It was obvious that he had spent time in prayer and Bible study and was consequently "filled with the Holy Spirit."