mǎn zhāo sǔn, qiān shòu yì 满招损，谦受益
Complacency Leads to Failure; Modesty to Success.
Conceit and complacency cause failure whereas modesty and prudence bring success. Ancient Chinese believed that all things were in constant change, and advantages might turn into disadvantages, and vice versa. One should keep pace with the times, work hard and never be complacent about what has been achieved; and one should keep a low profile, be modest, and be eager to overcome his weakness. The same applies to either an individual or a nation. This belief echoes the Chinese character of endeavoring ceaselessly for self-improvement.
Complacency leads to failure, while modesty to success. This is a universal law governing all things under heaven. (The Book of History)