A Brit in Denmark:
The rudeness of people is a shocker. They say they're just blunt, but it's extreme. I don't feel much warmth from people and they are very hard to get close to. You eventually stop trying.
Very young children just wandering/cycling around on their own, to and from school etc. Parents aren't very watchful of their children in malls etc, either. I've lost count of the times i've said to my partner "if that was the UK, that kid would be gone by now." But i'm starting to see it as a good thing. In the UK we mollycoddle kids, probably rightly so due to the crime levels. Here, crime rates are very low and i don't sense the same fear for wrapping the young in cotton wool.
Flags. You cannot fly any other flag than the Danish one, despite most gardens having a flagpole. Your neighbour's will grass you up to the Kommune, no hesitation!
Kids start school, at earliest, when they are 6 and it's all very outdoorsy and sporty.
Going into a cafe at 10am to find most people sitting with a pint of beer or glass of wine instead of a coffee.
The country seems to shut down in October and not open again until April/May. Most castles/historical buildings/places of interest close. I'm surprised they've much tourism outside of Copenhagen.
Food and cars are extortionate!! In fact, everything is. We do a big food shop in Germany once a month and buy 99% of things online to be sent from the UK.
Taxes are almost 50% But the work hours and work culture is far better. 8am - 3.30 and Friday is a 2pm finish.