have a mind as open as a valley-be extremely modest (/open-minded); be free from pride and prejudices;have a mind open to all ideas and thoughts; have no preconceived ideas;make a great show of humility; not biased ? 鄭孝胥為了拉攏下級司員，表示～，傾聽下情，……(愛新覺羅·溥儀《我的前半生》160) In order to win over his subordinates Zheng made a great show of humility and of listening to what they had to say.
虛懷若谷
have a mind as open as a valley;be of receptive mind;be extremely open-minded;be very modest
虛懷若谷xū huái ruò ɡǔ
谷：山谷。形容人胸懷謙虛，如同山谷一樣深廣。be very modest, great humility, not biased, be extremely open-minded