It's odd returning to a city where you've lived before. Some routes and neighborhoods you remember perfectly; others, once clear, have blurred in your memory, like the crayon rubbings children make of leaves or tree bark. Equally disconcerting is the realization that the mental spiderweb of maps, routes and information you acquired about your now-former city is of no practical use. Which metro route to the airport is easiest for travelers with a heavy suitcase? It doesn't matter anymore; that airport is an ocean away, and this one is only accessible by car.
Back in your new-old city, your friends give you directions full of street names that enter your ear with a vague feeling of recognition, like the refrain of a half-forgotten song. "Sunnyside Road..." you murmur, trying to buy time. "Is that on the southeast side?" Sometimes while driving in an unfamiliar part of town you come upon an intersection and realize you know exactly where you are. And always, your mind is at work dredging up knowledge you had forgotten you had: That restaurant has great salads. This trail leads back to the creek. There's street parking on the next block.
About a year ago, when I was still living in Madrid, I visited a friend in the Spanish city of Lleida. She insisted on taking me to see the city hall; I thought this sounded less than scintillating, but agreed anyway. It turned out that the city, upon beginning an expansion project during the 1990's, had discovered that the building was directly on top of a structure dating from Roman times. It was a little surreal to walk from the stately, ornate municipal interior down a wooden staircase into the deep, dank cavern below. As my friend pointed out the Roman baths (which still boast some stagnant water) and the small prison above them, I thought about the incredible coincidence of the city hall being built right on top of an already-occupied site.
Now, back in my hometown and struggling to remember things I definitely used to know, I've started to think my brain and Lleida's city hall have a certain amount in common. As you accumulate knowledge and experiences, it's easy to feel like the new information is crowding out the old. But like the city hall in Lleida, the mind harbors relics from long before. Your previous knowledge is still in there somewhere; all it takes is a little digging.