OMG! A Plastic Castle!

Alright, so I've used this phrase a few times in the last weeks or so, and recieved confused stares as people didn't understand what it meant. I figure now is high time to rectify that....as I thought it was a fairly common phrase.
The first time I remember hearing (or reading, i guess) it was on the VN Boards several years back. Since then I've adopted it as a perfect description of ADD people (you know, most everyone I know). You know, like people who continually get so distracted it takes them 8 hours to return a text message or maybe like people who somehow cover 8 topics in one sentence or even those damn people that are continuously distracted by sports on TV during conversations. You know the type.
So you're asking yourself, what does this have to do with plastic castles? I don't know why you're asking yourself that, I'm obviously going to answer. What you have to do, is imagine that these people are goldfish. No, not the delicious crackers (I prefer parmesan), but the little fish. And that they're swimming around in a little fish bowl....and that inside this fishbowl there is sand, a plastic castle, and two fish.
As the fish swim around, one is continually trying to have a conversation with the other. It will say something like, "wow, this fish food sucks, don't you think?" and the other fish will reply, sometimes....but everytime they lap around the bowl the latter fish will see the plastic castle and blurt, "Oh My God! A Plastic Castle!"
And the conversation will get derailed.