hammer (something) into (one's) thick skull(redirected from hammer it into his thick skull)
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!