5 ideas
Land, rank and stored wealth can be confiscated or made worthless when a regime falls, but a skill carried in the person moves with its owner into whatever order comes next. Reading and literacy count as the most portable of these skills, because every new ruler needs people who can read, write and administer.
Under the Southern Liang, young aristocrats perfumed their clothes, wore high-soled clogs, rode everywhere in carriages, and could not ride a horse or say when crops should be sown. One official is said to have mistaken a neighing horse for a tiger. After Hou Jing's rebellion and the fall of Jiangling in 554, these men starved or were carried off as captives. Captives who knew the Analects and the Classic of Filial Piety could still find work as tutors, while the unlettered heirs of great families were set to ploughing and tending horses.
A Northern Qi official boasted that he was teaching his son the Xianbei language and the lute so the boy could serve and please the ruling nobles, and he called this a sure path to advancement. Yan tells his sons that even if such accommodation made them chief ministers, he would not want them to do it. The case marks his limit: learn skills that carry you through any regime, but do not turn yourself into an instrument of flattery toward whoever holds power.
Instruction should begin once an infant can read faces and understand approval and disapproval. That is when correction costs least, because no habits yet need breaking. Parents who indulge a child and then try to impose control later meet hardened arrogance, and the resentment ends in punishment without effect. Yan's formula is that strictness joined to affection produces filial and careful children, while affection without strictness produces ruin.
A family should set explicit ceilings on what it holds, such as a modest number of servants, enough land to feed itself, and middling office. Wealth and rank beyond that level draw envy, suspicion and confiscation when power changes hands. Visible surplus is exposure rather than security, so declining to rise too high is a deliberate way of surviving.