The wind{The same Greek word (pneuma) means wind, breath, and spirit.} blows where it wants to, and you hear its sound, but don't know where it comes from and where it is going. So is everyone who is born of the Spirit."
The person born of the Spirit is similar to both the Spirit and the wind in that it is impossible for unregenerate people to understand or control him or her. They do not understand his or her origin or final destiny. Nicodemus should have understood this too since the Old Testament revealed the Spirit’s sovereign and incomprehensible working (e.g., Ezekiel 37).