Or the ways in which revisiting a city where you once lived is like seeing a person you were once in love with.

I lived in Prague for about a year and a half. It was a relatively short relationship, but it was intense too – the kind you have just after graduating from college. Since then, I’ve had some short-term flings with other cities like Los Angeles and Granada, Nicaragua. Then I got into a committed relationship with Buenos Aires. That’s another complicated story.

Anyway, this week, I went back to Prague (I’m working on a book for Lonely Planet.) Seeing the Czech capital again – seven years after I first arrived, and more than five years since I left – has been surprisingly emotional. It’s not unlike seeing a romantic figure from my past. Here’s why:

Despite the mystique that grows in its absence, you’re instantly familiar with it when you see it again. My first day back in Prague, I was unsure of my own sense of direction, remembering how the streets twist and turn and have names like Pařížská třída and Na Příkopě. But once I started walking, I never even thought about taking out a map. I thought I’d forgotten. But I knew where everything was – I even remembered the shortcuts.

At first, everything might seem so great that you’ll forget why you ever left. It was a gorgeous fall day when I arrived in Prague this time. On my street, Czech hipsters were drinking beer at an outdoor cafe while a beautiful child wheeled her tricycle over crunching leaves; I could smell bread baking somewhere. I remembered how I felt at ease living here – how people are so mellow, how anything goes.

But after awhile, you start seeing the details that used to drive you crazy. The second day back in Prague, I saw no fewer than five men urinating in public – in broad daylight. I forgot what a common sight it is here. (And one of the men? I had actually noticed him as he approached, thinking, ‘that’s a good-looking guy,’ right before he turned his back to the oncoming passerby and started unzipping. I mean, come on.)

There’s a bunch of stuff you used to like that’s gone. But your experiences elsewhere now help you appreciate the things that are still here – things you once took for granted. One little cafe I used to go to has been replaced with a loud, busy Starbucks, one of many that have popped up downtown. But discovering this fact wasn’t a big hit to my day – it was only a seven-minute metro ride away from my apartment on one of the quickest, cheapest, most efficient public transportation systems in the world.

You’re looking at it, but it’s looking back at you, too. It makes you remember yourself the way you were then. Walking around Prague, I remember what it felt like to be cold,  to have no extra money for anything. I taught English to businessmen back then – I always had to wake up before dawn to make the commute to their offices by streetcar and subway. Oh, I was so innocent! I didn’t know how to cook anything, I’d never tasted a martini, I didn’t have an internet connection at my apartment. I read Milan Kundera and Boris Pasternak in cafes, careful not to let the waiter bring me a second coffee because I just couldn’t afford it. I wished I could be a writer.

Stuff you thought was cool before – just isn’t anymore. I had this one Czech student who was a hotshot thirtysomething real estate mogul. For our weekly ‘lesson,’ he would take me to this fancy sushi restaurant downtown. He’d order a bottle of expensive champagne and a ridiculous amount of food for us – he didn’t seem to care about whatever material I’d prepared for him. I used to think this was really great. Free sushi, right? But since then, I’ve been around the block a few times. I’m not 22 anymore. So when I walked by that place yesterday, all I could think was, ‘oh, how cheesy.’ Both the restaurant and the guy.

You realize it’s meant something to other people. It’s not just ‘your thing’ anymore. On Saturday, there were three American girls – fresh off the boat, so to speak, training to become English teachers – sitting next to me at Cafe Louvre. It occurred to me that they’re just starting their own love affairs with the city.

You’re probably not going back permanently. But something still pulls at your heartstrings. You look at it with a particular kind of affection. It’s the kind of affection you can only have for a person – or a city – you once loved dearly.

Here’s to looking back.