Conrad's reflection, including his quote, sums up fairly well what we are up against, at a personnal and collective level.
We live in a world where each of us is prey to a thousand influences and sollicitations many of them unnatural, and this can only accelerate with today's widespread means of communication. To live with or in simplicity would be far from obvious even if conditions were ideal. Even in a quiet, truly sane and nourishing environment one is prey to likes and dislikes, one may find himself or herself brooding over some deception and give in to the illusion that the grass is surely greener elsewhere. This tends to happen all too 'naturally'. Psychological unrest, by itself, creates disorder and attracts unwanted= unnatural conditions.