to have somebody or something on the brain
[have] {sb/sth} on {one's} brainto have somebody or something on the brain
01
to be unable to stop talking or thinking about someone or something
Idiom
Informal
예시들
Ever since the breakup, he has had his ex-girlfriend on the brain, constantly reminiscing about their time together.
She has a big presentation tomorrow, so she has work on her brain and is diligently preparing for it.
