get it into one's head

get it/sth in/into one's head (become possessed of an idea; develop a fixed idea) — втемяшиться в башку, вбить себе в голову; взбрести кому-л. в голову; ~ зациклиться

Example: She's got it into her head to become a singer and nothing we could say would make her change her mind.

See also
[вбить в голову]