Jackson's peculiar personal traits contributed to his unpopularity as an educator. With little sense of humor, he once tried to get a cadet dismissed from VMI for playing a prank on him. He was a hypochondriac who had sinus problems and arthritis and stood for long periods of time to keep his internal organs in place, a tiring activity that he believed contributed to good health. He rarely ate much food and often subsisted on crackers and milk. He required little sleep but was known to take catnaps. He liked mineral baths.