學然後知不足

to learn is to know one's ignorance (the Book of Rites 禮記|礼记[Li3 ji4])

no; not so / (bound form) not; un-

to know / to be aware

excessive

foot / to be sufficient / ample

back / behind / rear / afterwards / after / later / post-

correct / right / so / thus / like this / -ly

insufficient / lacking / deficiency / not enough / inadequate / not worth / cannot / should not

to learn / to study / to imitate / science / -ology

after / then (afterwards) / after that / afterwards

then; after that; afterwards