Did I live in another city than the author? I constantly see people doing selfies since it came in fashion. I lived there for decades (born there) and I travel

Did I live in another city than the author? I constantly see people doing selfies since it came in fashion. I lived there for decades (born there) and I travel around a lot. Still don't see any difference. Just go to the Brandenburger Tor, and you will see a massive amount of people doing selfies. Or is it actually about the people, Berlin people or germans in general? But who then is actually Berlin person, a city where less than 50% are actually born there (probably the same in many big cities). I'm kinda confused and was even surprised after reading the title.