2. This idiom comes from Lu's "Reply to Cao Hui's Book of Scholars": "My brother is afraid of deer and fish, and it is not enough to be a tripod."
3, so when using deer, deer, fish and fish, it can be used to describe some very mediocre people, and it can also be used to describe yourself. It is also a kind of self-modesty, but be careful not to use it wrong to avoid embarrassment.