天高地厚 high as heaven, deep as earth, (of kindness, friendship etc.).; complexity of things; profound; immensity of the universe
不知天高地厚 not to know the immensity of heaven and earth -- have an exaggerated opinion of one's abilities; not to know how high the sky is and how thick the earth is; not to understand things; not to understand things
What is worth pondering over is the worried feelings hided behind the fantastic stories in which jin yong felt the solemn , strring and loneliness facing the tiredness and lose of chivalric spirit before he stopped writing 值得回味的是掩藏在传奇故事背后那令人揪心的切肤之感,因为在这当中,融铸了金庸封笔之前面对侠义精神的委顿和失落所感受到的天高地远般的悲壮寂寞。