Galatians 1

After his miraculous vison and conversion, Paul recounts what he did afterwards writing -

"...immediately I conferred not with flesh and blood:
17 Neither went I up to Jerusalem to them which were apostles before me; but I went into Arabia, and returned again unto Damascus.
18 Then after three years I went up to Jerusalem to see Peter, and abode with him fifteen days.
19 But other of the apostles saw I none, save James the Lord's brother.
20 Now the things which I write unto you, behold, before God, I lie not."  (New Testament | Galatians 1:16 - 20)

It was during this period he tells us -

"...I certify you, brethren, that the gospel which was preached of me is not after man.
12 For I neither received it of man, neither was I taught it, but by the revelation of Jesus Christ."  (New Testament | Galatians 1:11 - 12)

I believe that during this period, Paul spent a great deal in prayer and studying the words of the prophets (revelation).  If find it interesting that by study and prayer, a great understanding of the gospel was learned from the Old Testament having its mysteries revealed to him.

I too find that as I study the scriptures in faith, greater understanding and knowledge to my convincing are continually received.