It takes getting used to, but nothing stays new forever. Prompto understands where this guy's coming from. He focuses on that, rather than the whole bit with the walls. Because that sounds like a barrel of crazy and he's had enough of that for quite awhile.

"Just have to adjust, I guess. My world's a lot different than this place, so it might take awhile." But he'll get there. And immediately he hates himself for the sentiment. He should be trying to find a way back, not settling into this place. Noctis and the others need him. They have to be looking for him, wondering what happened.

If they haven't just written you off and moved on.

No no, there's no time for thoughts like that.

"O...kay? What do you want to show me?"