小时候幸福很简单长大后简单很幸福
[xiăo shí hòu xìng fú hĕn jiăn dān zhăng dà hòu jiăn dān hĕn xìng fú]
The saying is divided into two parts: 'When young, happiness is very simple', 'As an adult, simplicity is very happy'. It compares childhood's simple sources of joy to adulthood where finding simple things again brings contentment, highlighting changes in life priorities as we age.