大勇若怯

a great hero may appear timid (idiom); the really brave person remains level-headed

see 大夫[dai4 fu5]

big; large; great / older (than another person) / eldest (as in 大姐[da4 jie3]) / greatly; freely; fully / (dialect) father / (dialect) uncle (father's brother)

brave

to seem / like / as / if

timid / cowardly / rustic / Taiwan pr. [que4]

a great hero may appear timid, the wise may appear stupid (idiom); the general public may not recognize great talent