When I translate English into Korean, or vice versa, I often feel that I'm "unzipping" a file that would lie neatly compressed in its original language; sometimes I find myself so embarrassed with all the sub-files "newly" created in the orher.
Other than the contents, you have to bother to translate between the lines, say, the context as well. But just as a good poem resists to the death its reduction to a flat statement, a good translation defies paraphrasing.