this time he enlisted in the air force ( recently liberated into its own branch of the services - formerly the army air corps ) and in one of those million-to-one incidents that sometimes happen in life , the higher-up matched an enlisted man with his aptitude and set him to studying electronics under men who knew the hardware and the math , and he soaked it in like a dry sponge , studying electrons and radiometry and then their applications in communication and navigational systems , and more , and he passed all of their tests and made up lessons of his own and what he learned he sometimes shared but more often kept to himself , because the first thing any enlisted man ever learns is to never volunteer .