Subway Memory.

When I was in kindergarden, my mom and I often visited my grandparents by taking Seoul subway line 3. As a child, I was fascinated by every aspects of the extraordinary urban infrastructure; underground tunnels that are connected like a giant spiderweb, trains with metallic gloss making screeching metallic sound, diverse of passengers from a homeless to a white-collar commuters, etc.

One of my most cherished childhood memories is, standing on the platform while holding my mom's hand and waiving at the train that is slowly heading into the darkness. Best part of it was, of course seeing a train conductors who waved me back.

It's been a decade and many things have changed.

There are now 15 subway lines in the Seoul Metropolitan area, but I am no longer a constant passenger.

Instead, I've been riding the New York City's MTA and Philadelphia's PATCO in the past month.

From this month, I'm becoming much familiar with the names of Toronto's TTC stations.