The saying warns against striking too high, or a chip might fall into your eye.

VOA: special.2010.01.17

Many people said the problem with general levels of happiness or unhappiness rather, the cause is people have too high expectations.

很多人说,一般的快乐或不快乐水平，是由于人们有过高的期望。

哈佛公开课 - 幸福课课程节选

And not be too critical or expect that you should be at a very high level when you're just beginning.

不要太挑剔，也不要奢望自己刚开始的时候就可以达到很高的水平。

学外语的时候 - SpeakingMax英语口语达人