Talk:Elsa Granhiert/@comment-2.51.47.106-20200329103855/@comment-62.143.165.187-20200721034239

It's basically the same as "don't judge a book by its cover" but usually used for calm and quiet people. Even someone calm and quiet might know or do things you would never imagine. Of course it can not only be used for the quiet ones but in general if someone shows unexpected behavior.