The literal meaning of this idiom: Think the child is clever, doubt the neighbor.
The story about this idiom
宋国有个富人,因下大雨,墙坍塌下来。他儿子说:“(如果)不去(赶紧)修筑它,一定有盗贼进来。”他们隔壁的老人也这么说(可富人并没有理会)。这天晚上果然丢失了大量财物,这家人认为自己的儿子很聪明,却怀疑是隔壁那个老人偷的。
once upon a time, there was a rich man who had a large house. One day, the heavy rain damaged his wall. His son said to him, "If we do not rebuild the wall, we must be stolen by thieves." At the same time, the rich man's neighbor, an old gentleman agreed with the rich man's son. However, the rich man didn't pay attention to the notice. As his son and the old man said, the rich man lost many treasures in the night. Thereby, he thought his son was very clever. However, he thought that the old man was the thief.
Learn Chinese idiom and think - what can we learn from this story?