For years I have been saying それが人生{じんせい} in Japanese to mean "such is life" / "c'est la vie". Japanese friends always understood, seemed to enjoy it, and never corrected me.

On my current trip to Japan I also learned 仕様{しよう}が無{な}い as having a similar meaning, perhaps literally more like "it can't be helped".

But only this morning for the first time have I been told that the first one is not actually a set phrase in Japanese, that it's merely the literal translation of the English (or French) phrase into Japanese.

So is it true that only 仕様が無い is used in idiomatic Japanese or is it just that the person who corrected me just isn't used to それが人生 even though other people in other parts of Japan, or people of other generations, might use it in their normal speech?