I am from Poland. My first name is Łukasz (Lucas).
I have only The Book of Lost Tales (three parts in Polish) with myself. I have also LoTR and the Unfinished Tales at home (as well as The Adventures of Tom Bombadil, Farmer Giles of Ham and Smith of Wootton Major). I have read most other book that appeared in Polish from libraries. I did not understand or remember much from the original Silmarillion from 1977.