What does a bolt from the blue mean?

A bolt from the blue is a metaphor for a sudden accident.

A bolt from the blue, China idiom, pinyin for qíngtiāNPιLi, source: Song Dynasty's "Four nights before a chicken crows": "Let Weng fall ill and suddenly get drunk. Just like for a long time, the sky is flying. "

Idiom usage: subject-predicate type; As subject, object and attribute; A shocking example of idioms with derogatory instructions: Bing Xin's Lao She and the Children: "This is the voice I heard. How can such an energetic person die? "

Make sentences with a bolt from the blue:

1, but the teacher's words that I want to take home for my parents to sign, like a bolt from the blue, scared me out of my wits.

Mother was ecstatic after hearing the news, but my mood was like a bolt from the blue and I was very depressed.

Suddenly my mother shouted, and I felt like a bolt from the blue. I hurried upstairs to do my homework.