One can study for ten years in obscurity, but as soon as one passes the examination the whole world pays attention.

解释 ( paraphrase )
在寒窗下苦读十年，没人理睬；一旦考中了，则闻名天下，身价百倍。
这条谚语告诉我们：在过去的科举时代，读书人只有靠苦读诗书，考取功名，才能够出人头地。

This proverb encourages us to persevere despite the fact that no one seems to take any notice, for fame awaits at the culmination of a long period of toil.

同义词 ( synonym )
吃得苦中苦，方为人上人。

造句 ( example )
大多数农村父母都希望自己的孩子能够用心读书，将来衣锦还乡,光宗耀袓，实现所谓“十年窗下无人问,一举成名天下知”。