Summary
The aphorisms fall into loose groups. Several put art and artifice first: the first duty in life is to be as artificial as possible, style matters more than sincerity in all matters, and one should either be a work of art or wear one. Others turn morality around: wickedness is a myth of the good, telling the truth gets one found out, and any concern with right and wrong shows arrested development.
A third group mocks work and seriousness: industry is the root of all ugliness, time is waste of money, and dulness is seriousness come of age. The last sayings praise youth, idleness and the self, and pity the young men who end in useful professions, from 'the young know everything' to the closing line on loving oneself.