Castiel was an angel so obviously he never fully understood all things humans do- but he was learning. Currently you and him were talking and he brought up something called ‘shifting’ saying how it was an interesting concept about moving your consciousness to another reality and he didn’t think things like that were possible.

Unfortunately for you it made the conversation a bit more uncomfortable as now you figured would be the best time to tell him about how you yourself shifted realities but you just couldn’t find a way to properly tell him..