one-track mind
US /ˈwʌnˌtræk ˈmaɪnd/
UK /ˈwʌnˌtræk ˈmaɪnd/

1.
pikiran satu jalur, pikiran sempit
a mind that thinks about one particular thing and nothing else
:
•
He's got a one-track mind when it comes to cars.
Dia punya pikiran satu jalur kalau soal mobil.
•
All she talks about is her new project; she has a real one-track mind.
Yang dia bicarakan hanyalah proyek barunya; dia benar-benar punya pikiran satu jalur.