My sister Lisa came to Chicago just the other day. For two weeks — before I leave for other pastures — we’re roommates. And this makes me happy. We’re not usually in the same city, just hauling the same genetic baggage around our respective haunts. Now we can both say: Hey. That looks just like mine. We both mumble when we talk. Can’t follow compass directions. Love goat cheese and pasta and beer. Stay up late, watching Curb Your Enthusiasm and L’Auberge Espagnole and sipping through a $3 bottle of wine while our apartment’s ancient gas heater clangs and thrums.