hammer (something) into (one's) thick skull(redirected from hammer into their thick skulls)
hammer (something) into (one's) thick skull
To commit some piece of information into one's or someone else's long-term memory, especially through intense repetition. How many times do I have to hammer it into your thick skull? Do not drive my car unless I give you permission first! I've just been trying to hammer these formulas into my thick skull for the big test tomorrow!