German, only having been there once some years ago, so no idea if it still is that way:
Not knowing what I will have to pay in the grocery store until the cashier tells me what to pay. Here the price on the shelf is THE price. I might have a voucher that reduces the price in the end, but nothing is ever added only subtracted, all prices on the shelf are easily comparable, because no matter the weight of one package there is also given the price of 1kg or 100 g for everything.
No kids on playing grounds without parents standing around. No kids just playing on the side walk (often there is no side walk anyway), no kids walking to school. It made me aware of how much freedom kids have in Germany, how independent even 6 y.o. are in Germany compared to kids in the US. They walk to to school alone or use public transport alone, they buy groceries alone, they visit friends by foot or public transport, three y.o. already having a bike and cycling besides their parents to kindergarden…
On the other hand seeing so many very young people having a job, like a really hard job for many hours besides school. It broke my heart, they should be free to be young and having all the time, working comes fast enough and goes on forever. Also I saw very old people doing jobs that should be able to retire because you could see them being in pain and barely able to function, definitely not a “choice” for them.
The amount of medication, especially pain medication, people take in the US compared to Germany and how much of it is freely available while it is needing a subscription from a doctor here. Every time I was feeling unwell I was offered pills that I found to be numbingly strong and switching my brain off? Hard to explain. I found them scary, but was told that they take them on a daily basis and they are harmless … nope.
In the first region in the midst of the first small village two neighbors are arguing. They are not giving a quest, they just talk to each other and listening gives such an insight in how war can turn people against each other that have been living peacfully and been friends for years.
Do the side quests and take your time with the dialogue. Some of these stories are impactful, mostly sad and worth your time. If you are told that you should talk to people to find out more about your contract, do it. Some of these quests can be done with only talking to one person but you want to get the information from everyone and especially their side of the story.
Do not look up the outcome of decisions. Make your decisions and live with them at least at your first playthrough. Most decisions have impact and seeing the outcome unfold makes this game special and yes often there is no “good choice” - that’s war for you.
Last: Buy every Gwent card you can get your hands on and play with everyone you can. If you can’t win just come back later with better cards and obliterate them - it will feel goooood!
The DLC’s are a must.
Try out difficulty settings - there is a sweet spot for most people somewhere but what it will be for you no one can know, but it would be a shame if you play through the game not having found the difficulty that fits you best because you “always play on <insert difficulty>”.
Have fun, I wish I could play this game for the first time again.