be on the same wavelength/on different wavelengths

be on the same wavelength

To be in agreement; to think or behave similarly. I was surprised that we became friends so quickly, but we're just always on the same wavelength.
See also: on, same, wavelength

be on the same ˈwavelength/on different ˈwavelengths

(informal) have the same/different opinion or feelings about something: I find him difficult to talk to — we’re on completely different wavelengths.On the subject of marriage, Judith and I are on the same wavelength.