If I didn't know why I had one million in my account, chances would be it was an error and the money wouldn't legally be mine, and sooner or later the bank would catch the error. So I wouldn't be relieved, but I wouldn't be scared either. Even if some stranger sent me one million I wouldn't be scared. Maybe relieved? Maybe relieved and a little scared? I wouldn't be scared without being relieved too, though, because the only way I wouldn't be relieved is if I told the authorities and they took it away or something, and then I wouldn't be scared either.