I was thinking about that when I was dropping my 6 year old off at some hobbies earlier - it’s pretty much expected to have learned how to ride a bicycle before starting school, and it massively expands the area you can go to by yourself. When she went to school by bicycle she can easily make a detour via a shop to spend some pocket money before coming home, while by foot that’d be rather time consuming.
Quite a lot of friends from outside of Europe either can’t ride a bicycle, or were learning it as adult after moving here, though.
edit: the high number of replies mentioning “swimming” made me realize that I had that filed as a basic skill pretty much everybody has - probably due to swimming lessons being a mandatory part of school education here.
In Germany it’s also mandatory - but learning the language at school unfortunately doesn’t necessarily mean you can speak it. LucasArts adventures contributed more to my language skills than my first English teacher. I’m always shocked about the lack of English skills in a lot of Germans when I’m back visiting. Rather surprisingly one of my uncles born in the 30s spoke pretty good English, though.
We’re now living in Finland - me German, wife Russian, we each speak to the kids in our native language, between each other English. So they’re growing up with 4 languages.
It’s quite interesting to watch them grow up in that situation. When learning about a new historical figure my daughter always asks which languages they spoke - and few weeks ago she was surprised someone only spoke two languages. So I explained that some people only speak one language - she gave me a very weird look, and it took a while to convince her that I’m not just making a bad joke.