I've seen some people talk about an intense brett character from 1809. I've never experienced it. Maybe the brett character develops in the bottle, and you happened to get an older bottle?
1809 isn't actually that stylistically accurate. I know people can get hung up on trying to make beers similar to commercial beer, but if I were you I wouldn't compare my berliner weisses to others. It's all about how you want it to taste.