The Doctor is someone who, despite his career as a combat medic/mercenary, is very passive and timid. Though he's also done some questionable stuff such as doing surgery with no gloves or having spare body parts in his freezer as a (somehow still) licensed practicioner back in the UK. But worst of all, he has a SEVERE coffee addiction like jesus christ how hasn't this man suffered a heart attack already? He's as jumpy as a Crankenstein!