I was living in BKK as an expat for three years, and returning to northern Europe was really hard I have to admit. When I think back, then it was easier to adapt to life in BKK than life in Denmark, but that's maybe because BKK was some sort of adventure for me.
The things that were really hard to adjust back to was of course the food (Thai food is the best food in Asia!) and the cold weather in Northern Europe. And of course the boys. In BKK, you are in some neighbourhoods surrounded by heavenly beautiful boys all the time who are friendly and interested talking to you. It's a kind of hard landing going back to Europe where all younger guys play hard to get and are plain arrogant often. Spoiled, you could say. Even though there is very often a strong element of sexual attraction between farangs and Thai boys (and money too some extent too), it's hard to overlook the genuine non-sexual and non-pecuniar aspects of this: The curiosity, hospitality and their deep-grounded respect that characterises the younger Thai guys (with many exceptions of course).
About the people at work, then I was actually kind of happy to back in a European workspace with more people to talk during the day about politics, (pocket)philosophy and culture and to make jokes with. The humour in northern Europe is very much based on irony and sarcasm, which Thai people don't get at all.