'Alone' in the Bible

A man who is all alone with no companion, he has no children nor siblings; yet there is no end to all his toil, and he is never satisfied with riches. He laments, "For whom am I toiling and depriving myself of pleasure?" This also is futile and a burdensome task!

This alone have I discovered: God made humankind upright, but they have sought many evil schemes.