Fortunately or unfortunately, I've been able to witness, though from afar, two diagonally opposed manifestations of the most problematic collective ego - the ego of a nation-state - in the past few years. They are chauvinism and patriotism.
Ever since I had some traumatic experience with the collective ego of a junior high school I attended, I've come to show a very strong resistance reaction to the ego of any social collective, especially after spending there at least a few years as its member. Then I feel suffocated and unable to stand remaining there, and find myself leaving it for "fresh air", so to speak.
Chauvinism and patriotism are two manifestations of the same level of collective ego, but they have one fundamental difference. Chauvinists try to raise their self-perception by downgrading members of other social collectives such as dehumanizing and even mass-murdering them. So they are automatically upgraded by doing nothing for themselves. Chauvinism seems to be a result of collective brainwashing through constant propaganda in various layers of society.
Patriotism, on the other hand, seems to be a natural manifestation of one's love for the collective that has nurtured him. Genuine patriot doesn't have to sacrifice members of other social collectives.
Even before witnessing two disgusting cases of chauvinism in the past few years, I've always been repulsed by this social collective called nation-state. So in retrospect there is no wonder that every time I crossed any national border, I even felt like vomiting. But now I apparently underestimated the destructive power of chauvinism as I've been witnessing two of its cases being reported live.
On the other hand, I've also witnessed patriotism. In theory, it was also supposed to repel me, but to my great surprise, I've been deeply touched by it and even felt like supporting it wholeheartedly. When I recently shared this deepest feeling of mine with one of the few people I know who understand me, I was so overwhelmed with emotions and started crying.