Well, Happy Bulgarian anniversary! 
You do know the city better than many Bulgarians, even Sofians in particular, because while you make it a point to explore the city, a lot of people stick to their familiar routes, adopting an often subconscious "meh, it's not going anywhere" attitude.
Have fun in Walla Walla! Though you're home just in time for some more political craziness - http://blogs.discovermagazine.com/badastronomy/2011/07/07/congress-puts-nasa-and-jwst-on-the-chopping-block/ How on Earth did they decide that this is a good idea?