Definition from Wiktionary, the free dictionary
|simpl. and trad.|
Literally: There are people beyond (this) person, and skies beyond (this) sky.
人外有人，天外有天 (traditional and simplified, Pinyin rén wài yǒu rén, tiān wài yǒu tiān)
- No matter how good you think you are, there is always someone out there that is better.