As someone who attempted (and failed) to move to Prenzlauer Berg earlier this year, I can honestly say that it was really rare to interact with native Berliners because they were pretty hard to find. When I stayed in Wedding there were plenty of what you and I might call native Berliners, but locals wouldn't (mostly of Turkish descent), although I did find more in the Hansaviertel than the stats would show, but I think I was better at interacting with local people by then.