"The wind blows wherever it wants. Just as you can hear the wind but can't tell where it comes from or where it is going, so you can't explain how people are born of the Spirit." — John 3:8
The comings and goings of the Spirit of God is one of the things that are beyond human comprehension. God is the Sovereign Lord of heaven and earth who "lives in light so brilliant that no human can approach him. No human eye has ever seen him, nor ever will" (I Timothy 6:16). You can't, therefore, get close enough to the Lord to rationally analyze and comprehend Him or His Spirit. From within that brilliant light the Lord makes His decisions to send forth the Spirit in accordance with His sovereign will, not in accordance with any rational expectations or predictions we may come up with.
And that's why you can't rationally predict who will be born of the Spirit and who will not. It's a sovereign decision made by the Lord God. And that's also why you can't predict where the Spirit of God will take a person in life. That's also a sovereign decision of the Lord God. The Spirit of God enters and directs a person's life and no one can rationally explain it.
Jesus' analogy between the wind and the Spirit in our verse for today is helpful here. The movement of the Spirit is like the wind in that you can't tell where it comes from and where it is going, but you can certainly see and understand the Spirit's effects just as you can see the wind's effects.
Spiritually discerning people will know this. That is, people whose rational capabilities have been enlightened by faith born of the Spirit of God will recognize the effects of the Spirit. They will see and understand that the Spirit has been at work.
The Spirit is at work in us. We can't explain it or control it. But we can spiritually discern it and respond accordingly.
"Breathe in me, O Holy Spirit, that my thoughts may all be holy. Act in me, O Holy Spirit, that my work, too, may be holy. Draw my heart, O Holy Spirit, that I love but what is holy. Strengthen me, O Holy Spirit, to defend all that is holy. Guard me, then, O Holy Spirit, that I always may be holy. Amen"- St. Augustine.