get it into one’s head—
1. realize the significance of smth.:
- I wish you would get it into your head, once and for all, that I’m not made of money.
2. start to imagine or believe smth. without sufficient grounds:
- Somehow he got it into his head that everyone was blaming him.
Note: The expression does not correlate in meaning with the phrase get it through one’s head—figure out smth.; begin to understand smth.:
- I never could get it through my head how a car engine works.
take it into one’s head—
1. = get it into one’s head 2:
- Somehow he’d taken it into his head that his wife was trying to poison him.
2. decide to do smth.:
- If I should take it into my head to tell what I had heard, tremendous mischief could result.