It was my first time visiting Seoul in 2014 and I made a list of random things that I saw/experienced. You can read about my random observations series here.
1. Coffee shops are everywhere. Everyone is caffeinated.
2. Using a credit card is widely accepted (not in Japan).
3. The streets are louder and more lively.
4. They start drinking early and you can find drunk people walking even at 5pm.
5. Cheap beer and even cheaper soju at $1.
6. Of course Samsung is everywhere. From flat screens tv's at the airport to cellphones.
7. Super spicy foods.
8. A very modern city in touch with technology.
9. Super high speed wi-fi's.
10. They work very long hours!
11. Lots of outdoor markets for food, clothing, accessories, etc.
12. More people can communicate in English.
13. Skincare and make up stores are everywhere.
14. And so are plastic surgery clinics and advertisements for it.
15. They have showers only instead of having a bath tub.