1
general::
Phrase(s): *a bee in one’s bonnet
a single idea or a thought that remains in one’s mind; an obsession. (*Typically: get ~; have ~; give one ~.) • I have a bee in my bonnet over that cool new car I saw, and I can’t stop thinking about it. • I got a bee in my bonnet about swimming. I just wanted to go swimming all the time.
McGrawhill's American Idioms And Phrasal Verbs