have a lignt bulb go off in the head

题目

have a lignt bulb go off in the head
What does this phrase mean?
It's a metaphor.Head here refers to the human brain.The entire sentence is as following:
When they said little things,I could raise an eyebrow or have a light bulb go off.

答案

go off （电灯）熄灭
light bulb（ 不是lignt） 就是电灯泡
in the head 在顶端
have sth.do 就是让..做什么
这里的意思是：将顶端的电灯泡熄灭
嗯,如果是隐喻,意译就是：对什么事不在意或漫不经心的样子（关掉脑中警惕的那盏灯）