Rules of the (American) road
Yesterday, my dad dropped me off near their neighborhood on his way somewhere else. I had to walk for what seemed like half a mile (but I just checked - it was less) to get to a crosswalk to cross the street. And I thought, Finland would never stand for this! I have gotten so used to having crosswalks almost anywhere I need them. It is rare to have to walk very far to find a legal place to cross the street in Turku.
I had also gotten used to the Finnish model of delineated bike/pedestrian paths, which are separate from the road. In high-use areas, there is a full sidewalk for pedestrians next to a full pavement for bikes. In normal areas, there is just one pavement path for both to share. Both the double paths and the single paths are wider than American sidewalks, seen here:
Since being in America, I've had to remember how to make unprotected left turns (there are some of these in Turku, but not many) and how to act at stop signs. I had never noticed, until coming back to the US, how few stop signs are in Finland! Instead of stop signs, there are yield signs, or mostly just implied, unmarked yields. The lesser road gives way to the major road; if you're not sure, the car on the right proceeds first. I've also had to remember how to turn right on a red light here - that's not allowed in Finland.
It's definitely taken some getting used to, driving in the US again!