"Being in the Army also grounds me in reality and in my community. The tech world can be a relatively narrow cross-section of society. When I spend time with the Army I interact with the full spectrum of my local community. My squadron has nurses, carpenters, architects, police officers, unemployed people, veterinarians, warehouse workers, tree surgeons, railway engineers, pilots, firefighters. I get to interact with people from a variety of backgrounds, a variety of economic situations, with a variety of outlooks[...] More than just interacting with a cross-section of society, it means building a very high level of trust and depending on each other. When we’re in the field there’s absolutely nowhere to hide, with no privacy and no time-off, and you’ll need to manage to get along. There’s a big taboo of being ‘jack’ and not looking after each other or serving yourself before others."
I had a similar experience when I had to do military service. I don't think there's a better cure for narcissism than getting out of your head and comfort zone, doing something for and with other people in the real world. We should remember where the word 'narcissism' comes from. From Narcissus staring into his own reflection. So sitting in your room, reflecting on how totally not narcissistic you are is never going to be a solution.