One thing that surprised me is how noisy the inside of the cockpit of the Spitfire was - a whole lotta rattling and shaking. I'm also assuming they're Spitfire I's... either way, throw in the heat and cold issues you have, wind leaks and the noise it creates, fumes that leak in from the engine, cramped quarters of a Spitfire cockpit (it's REAL tiny), and throw in regular life issues for 20 year olds - being hung over, constant constipation from flying G-turns, head colds, terrible uniforms for flying, gloves, dirty glasses, humidity in the cockpit, mechanical issues from mass production...
flying any WWII early war aircraft took more courage and then skill to overcome all the minute harrassments you face as a pilot and then put the stress that "SOME IS SHOOTING AT YOU TO KILL" in another airplane. Or - you just saw your best mate die in a flaming wreck, and you still have to press on with your mission. Or - you downed a He-111 and saw the boys in her trying to bail out and some got out and others got killed...kind of things on your mind as a pilot.
Does any of that sound like a fun activity?