Knowledge is not innate to man, how can we overcome doubt?; We are not born with knowledge, how does one achieve maturity? (i.e. without guidance from a teacher - Tang dynasty essayist Han Yu 韓愈|韩愈)
是可忍，孰不可忍是可忍，孰不可忍shi4 ke3 ren3 - shu2 bu4 ke3 ren3
if this can be tolerated, what cannot? (idiom); enough is enough
孰料孰料shu2 liao4
who would have thought?; who could have imagined?; unexpectedly