I am back in Canada having repatriated from South Korea after living there for a total of almost 15 years. It's great to be back in Canada with the clean air and space, and of course, with family and old friends. I do miss Korea so much, though; the people, the places, the access to things. Life in Korea was easy in so many ways.
Here are some of the things I miss about Korea (not in any specific order):

A smaller local bus in Yongsan-gu, Seoul

1. Transportation
Getting around is so easy in Korea. The bus and subway systems work so well. The Kakao Bus App made things so easy and let me know where the buses were along the route and how long before the next one would arrive. The Seoul Subway App told me which route was fasted to take, which door of the train the transfer was at, and when I would arrive at my destination based on when I left my starting point. I used Kakao Maps or Naver maps to figure out combinations to get to wherever I wanted to go. Taxis were affordable. I got a lot of crazies but I also got several wonderful drivers, one whom some friends and I got to know as he would routinely show up when he knew we'd be leaving for work (several of us got together and took a taxi every morning rather than all taking buses and subway).
Many of the buses even had smiling faces to greet you as the came, looking just like the characters from the Korean cartoon Tayo.

At a bbq restaurant in Itaewon, Seoul

2. Food
Korean food is amazing. Korean barbecue restaurants everywhere, delicious and affordable. Almost anywhere you go you can find Kimbap houses (sort of Korean fast food), where you could get kimbap (rice rolls), or mandu (Korean dumplings), or rice dishes, or stews/soups with rice, any of which came with side dishes.
Living in Seoul I had access to so many great international food options, as well: Thai, Indian, Chinese, Korean Chinese, Nepalese, Moroccan, Middle Eastern, Ethiopian, Italian, Mexican, Spanish, South African, and others, most of which were not far from where I lived. Just down the hill, a few minutes from our place, were quite a few places that we frequented.

at Changdeokgung, one of the main palaces in Seoul

3. History
I love places with a good history. Old places. I like to imagine what things would have been like long ago. Korea has a very long history with so many events. The palaces and folk villages and historical sites all fascinated me. The palaces are such beautiful places to wander about.

Playing at Silmi Beach on Muuido, South Korea
Silmido is in the distance (Made famous by the movie, Silmido, based on a true events)

4. Travel within the country
As Korea is a small country, it is fairly easy to travel to other cities and places, whether you drive, take a bus, take a train, and in some cases, a ferry. In a few hours you could be on a beach on an island. You could be hiking up a mountain in the country side, surrounded by rice fields. You could be in a little fishing village on a tiny little island. You could be wandering down into a cave. You could be enjoying the hot water in a water park that is fed by a natural how water spring. You could be in a sculpture park somewhere in the middle of nowhere. You could be enjoying the nightlife in another city.
From Seoul to Busan (opposite corners of the country) is similar to the distance from Edmonton to Calgary (neighboring cities).
5. Community, Friends
Living in Seoul made the world so much smaller. I met so many people from so many countries. I have made so many friends, several of whom I will forever hold dear. Even people I didn't know formed the interconnected network of people who made my life what it was.
6. Access to other countries
Living and working in Korea gave me access to the world. I was able to travel to so many places. From Korea, even a long weekend could be turned into an international trip.
In Canada, other than going to the US, visiting another country is a big and usually very expensive trip to make.