When old enough, Brunt was enrolled at Ellesmere College, where his mischievous streak became quickly apparent through pranks and dares; once, while in the sanatorium with mumps, he slipped a laxative into the matron's tea. Nevertheless, he is fondly remembered at the school. It was while he was at Ellesmere that he contracted measles, resulting in his need to wear glasses. An enthusiastic sportsman, Brunt played cricket, hockey, rugby, water polo and wrestling. He was the only pupil at the school to tackle the headmaster while playing rugby, injuring the older man's knee in the process.