年少不知春衫薄最羡少年衣衫薄
[nián shăo bù zhī chūn shān bó zuì xiàn shăo nián yī shān bó]
'Not knowing the thinness of spring robes when young most envious are those youths' clothing' reflects on youthful naivety and envy, reminiscing on the simplicity and freedom of being young while clothed simply without care.