I Can See the Forbidden Zone Rules - Vol. 1 Ch. 3

[MangaDex]

 

[-Kellam-]

So he’s been trapped with his sister and grandfather for seven years because… no one ever thought to close their eyes while crossing? Are we serious?

 

[VooXoo]

Yeah, very stupid that he "tried everything" aside just walking in it with eyes cosed or when it was too dark to see.
Possibly even walking backwards in the wall would have worked as the point was to not see it.
And he couldn't control the power but suddendly was able to do it to see the wall rules, that were never hinted to exist, dumb.