take something into one's head
Fig. to get an obsession or overpowering idea into one's thinking. George took this strange idea into his head about fixing the car himself. I don't know why she took that strange idea into her head.
take into one's head, to
To conceive an idea. This vivid image of putting an idea inside one’s head was already known about 1700. Joseph Addison used the expression (The Spectator, 1711): “When every Body takes it in his Head to make as many Fools as he can.”