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.
A few methods that come to mind
You got me thinking for a moment there but that thing’s called a mortise.
Aren’t they talking about the strike? I thought the mortise was where the lock goes.
I’ve never heard “strike” so I assume you know more about doors than I do.
I don’t know which one of us is right but rather than looking it up I’m hoping someone that actually knows swings by.