The Italians have a phrase, "traduttore, traditore". It means "translator... traitor".
Any translation depends on the talent of the translator - it's not enough to be an efficient translator, skilled in both languages; you also need a sense of poetry AND a huge cultural sensitivity. For both languages.
And some cultures don't translate. Explained yes, perhaps, but not translated.
Then there's always writers like Beckett, who translated their own work... :)