Duncan quickly adjusted his expression and mindset to avoid looking like a "foreigner" with disordered common sense, yet his thoughts could no longer calm down, churning like stormy waves.
As it turned out, when you suddenly find yourself in a bizarre and extraordinary world, no matter how strong your adaptability or how well you disguise yourself, you might be blindsided by some seemingly mundane "common sense" at any time—the kind that makes you exclaim an astonished curse when confronted head-on. Ordinary historical knowledge could be systematically learned, complicated professional knowledge didn't need to be considered in daily life, but "common sense" was something that could catch you off guard.
In this world's sky, there are no stars; this is common sense.
The stars of this world are in the Mysterious Deep Sea, at the boundary between the Spirit Realm and the Mysterious Deep Sea; this too is common sense.