I have spend one and a half years in Tanzania. The first things that really challenged me when I got back to Germany where:
-compared to Africa the people in Germany were practically "running" on the street. The average speed of a pedestrian in Germany is about the same speed of an African who is on the run of something. Furthermore all the public transport was punctually and on time, just as the schedule said and really meant seriously. So in the beginning I was always too late, where ever I went. And the people were not amused.
-German people who are working in public authorities are very emotionless, sterile, free of every privacy. I felt a bit sad not being asked about anything besides my official aims, only with rude glances. However and suprisingly, if I broke this situation by smiling and talking funny stuff, people also changed and became friendly and funny.
-Africans are mostly living from one day to the other, not making big plans about what is going to come next. This is impossible in Europe. Every day life in Germany is just full of making plans of something, (money) investments, insurances, rent, work itself, house repairs, car checks etc... So while a lot of time I had in Africa was only for my pleasure and if I had problems they were solved here and now, in Germany a lot of my spare time was suddenly lost to plans, creating and collecting documents, again plans and again collecting documents. And it is regarded as being infantile and lazy in Germany not to do so.
-On the other hand I was really overwhelmed by German hygiene and the standards Germans have made to keep them. Of course Central Europe isn't in the tropics, but it was really a relieve for me not to care about what food I eat, what water I drink, what insects might come here or there as well as any other dangers I was previously confronted with (crime, sunburn, unsafe vehicles etc...).
I would propably find even more things but that was my first impression I had when I came back.