That was really fascinating. It seems to be an ongoing theme that he likes to not give too much away so that each listener can have their own interpretation of the song. It's why I'm always surprised when people suggest he writes like Springsteen; not that there isn't some influence there, but Springsteen is very much a storyteller, at least most of the time. The settings, characters and stories are usually very clear, and what makes them so beautiful is that you can completely understand and empathise with the story even if you have no relevant experience. It's not about inhabiting the story yourself, but about getting a feel for the characters and their situation.
Whereas Brian's songs are a lot more obtuse, and you kind of have to work to figure out what they mean. This inevitably leads to you bringing in your own experiences, and then they end up meaning more to you because you feel closer to them. It's more like writing poetry than short stories I guess.