Moonesinghe went on to University College Ceylon (which later became University of Ceylon), where he excelled in athletics, representing his University at the All India Universities Athletic Meet, which was held regularly in those years, in Lahore in 1944. He taught briefly at Royal Primary School, which had been evacuated to Glendale Bungalow, Bandarawela. He won an exhibition to the University of London and went to Britain in 1945. He sailed on board a troopship; when the news of Churchill's defeat at the general election came through, all the soldiers on board threw their caps in the air and cheered, a fact which greatly encouraged him.