Л-61

КАК В (ТЁМНОМ) ЛЕСУ coll как + PrepP these forms only subj-compl with copula (subj: human) one is completely lacking in comprehension or understanding of sth. : X как в тёмном лесу - X is completely in the dark X is all (completely) at sea X is totally lost.

Сочинения (Кирилл) писал посредственно, почерк ужасен, в математике соображал слабо... Английский язык? Ну, разве что. В детстве силой заставляли ходить в английскую группу... Но ведь только лексика, а в грамматике - как в лесу (Трифонов 5). His (Kirill's) school compositions were mediocre, his handwriting abominable, and he was weak in math . His knowledge of English? Well, that at least was something. When he was a child we had forced him to join an English language group. But even so, all he had was a large vocabulary. When it came to grammar, he was completely in the dark (5a).

«Выслушайте же до конца, но только не умом: я боюсь вашего ума сердцем лучше: может быть, оно рассудит, что у меня нет матери, что я была как в лесу...» (Гончаров 1). "Hear me out, then, but not with your intellect-I'm afraid of your intellect-better with your heart, perhaps it will realize that I have no mother, that I was completely at sea. " (1a).