"Seven Sorrows", which the ancient Chinese poet Cao Zhi wrote about: sadness from a long separation from a scientist friend living in obscurity and poverty; sadness from the powerlessness to help the weak and humiliated; sadness at the thought of the futility of noble aspirations and courageous impulses; sadness from contemplating the ugliness of the world, from the lies and hypocrisy of court flatterers; the sadness of women's rooms and a lonely bed; the sadness of a lonely traveler in his endless wanderings; the sadness of a poet at the sight of national disasters, extinguished hearths and silence in once noisy villages.