There was a simple reason that Zain had survived in the new zombie world out there so far. At least it was the reason he believed he had survived for so long, and it was because he treated everything like a game.
The many survival games he played were ones where one made the best decision at the time for the situation. In real life, there were times where feelings, emotions and more were in play. However, in his zombie body he had learned somewhat how to disregard this.
It never felt very real to him, due to his new body, the emotions were numbed down on top of every other feeling. Yet here, in this what he assumed was a vision, it wasn't the same.
He could feel his heartbeat, was alive, and his senses were sharp. When trying to put himself in a game situation, once again he found it difficult, which had allowed him to think a little more clearly.