I saw this aphorism in my book of aphorisms.
담벽하고 말하는 셈이다
dam.byeok.ha.go mal.ha.neun sem.i.da
brick-wall-WITH talk-PPART guess-BE
[One could] guess it's [like] talking to a brick wall.
This is exactly the same as the English expression, "like talking to a brick wall." It's not so often I find exactly matching aphorisms. Perhaps dealing with dense individuals is a human universal.
[daily log: walking, 1km]