be modest about one’s talent (/learning); not be given to boasting (/showing off)
❍ 这位年轻人～，将来一定很有出息。This young man is always modest about his learning. He is sure to have a bright future.
深藏若虚shēn cánɡ ruò xū
虚：空。深深地隐藏着，好像什么也没有。比喻身怀真才实学的人不在别人面前显露。be modest about one’s talent or learning, not be given to boasting or showing off, hide one’s light under a bushel