Schadenfreude as a concept existed in English long before the word appeared in English and I am sure Polish speakers feel disturbed at times even if they don't have a precise word for it. Human emotions and feelings are universal hence why they can all be expressed in all languages.

The concepts that can't be expressed in all languages are those that are abstract and technical. A nice simple example of this is in some Australian Aboriginal languages there are no words for numbers of objects higher than 3 (they just become many). It really is impossible to translate the number 14 into these languages as the corresponding concept just doesn't exist.