Berlin is an odd place...
It was an isolated "outpost" during the Cold War - leading to things such as the Berlin blockage/airlift.
And I've been told that for at least some of that time, there was a policy whereby students could avoid national service by volunteering to live/study in Berlin [*].
So it's always had a left-wing student bent, and when the wall fell, the east side of Berlin had less industry and generally was in far worse condition. Cue lots of people shifting about, as people shifted from east-west for jobs and students shifted from west-east for cheap accommodation.
Fast forward to today, and you've still got some aspects of that hanging around. There's still a number of large "squats" and communes. It's amazingly dynamic, with throngs of international students and entrepreneurs; you'll hear people talking in English wherever you go. There's street markets, anarchistic bars with no windows, where photography is banned [**] - and large swathes of the city are blurred out on Google Streetview. It's incredibly cheap for a capital city: generally, it's closer in pricing to Sheffield than Manchester or London, you can have a good meal for under 20 quid and there's still a few bars where a 500ml bottle of beer costs just one euro.
OTOH, the city is flat broke, renting an apartment can be an absolute nightmare and the administration has been trying to sell off anything it can get it's hands on with few or no strings attached. So large scale construction has kicked off and is meeting some fairly stiff resistance from the various left-wing groups.
For better or worse, money is winning, and Berlin is slowly transforming into something closer to London.
[*] According to the bloke wot ran the street-art tour I went on. He also mentioned that where developers have tried to use famous street-art pieces as a selling point, the artists have often returned to paint over their own works in protest, such as the docks near Oberbaumbrücke.