Are you sure that it wasn't the Holy Spirit who changed your heart? The Bible is clear that it is God who changes hearts. And the Bible is clear the the gospel will be foolishness to you until your heart has been changed:
1 Corinthians 2:14 But the natural man does not receive the things of the Spirit of God, for they are foolishness to him; nor can he know them, because they are spiritually discerned.Chew on that verse...
Did the Father bid the Prodigal Son to return to him or did the Prodigal Son choose to return? Chew on that as well.