I didn't realize I was born again until someone explained what it was. So I think I was born again a long time ago when I fasted for 3 days and had a darkness leave my soul. Then I had a spiritual awakening. And that was probably being born again. But I only slowly learned what good was and it's been a long road since. About 25 years.
This is where it comes from. :) Basically it is when you come to know Jesus Christ.
John 3:1-17
1Now there was a man of the Pharisees named Nicodemus, a leader of the Jews. 2He came to Jesus at night and said, “Rabbi, we know that You are a teacher who has come from God. For no one could perform the signs You are doing if God were not with him.”
3Jesus replied, “Truly, truly, I tell you, no one can see the kingdom of God unless he is born again.a”
4“How can a man be born when he is old?” Nicodemus asked. “Can he enter his mother’s womb a second time to be born?”
5Jesus answered, “Truly, truly, I tell you, no one can enter the kingdom of God unless he is born of water and the Spirit. 6Flesh is born of flesh, but spirit is born of the Spirit. 7Do not be amazed that I said, ‘Youb must be born again.’ 8The wind blows where it wishes. You hear its sound, but you do not know where it comes from or where it is going. So it is with everyone born of the Spirit.”
9“How can this be?” Nicodemus asked.
10“You are Israel’s teacher,” said Jesus, “and you do not understand these things? 11Truly, truly, I tell you, we speak of what we know, and we testify to what we have seen, and yet you people do not accept our testimony.
12If I have told you about earthly things and you do not believe, how will you believe if I tell you about heavenly things? 13No one has ascended into heaven except the One who descended from heaven—the Son of Man.c 14Just as Moses lifted up the snake in the wilderness, so the Son of Man must be lifted up, 15that everyone who believes in Him may have eternal life.d
16For God so loved the world that He gave His one and onlye Son, that everyone who believes in Him shall not perish but have eternal life. 17For God did not send His Son into the world to condemn the world, but to save the world through Him. 18Whoever believes in Him is not condemned, but whoever does not believe has already been condemned, because he has not believed in the name of God’s one and only Son.