Oh, they master it, do they? So, you'd let a child who's been riding a bike for a week or so ride with heavy traffic, right? They've mastered it, so there's nothing else for them to learn.

There's a huge difference between being able to handle a bike at 5 mph, 15 mph, and 28 mph.

20 year old me who just ate pavement because they didn’t know how to safely navigate street car rails would disagree.

That was 40 year old me a couple years ago. Street car rails are terrible, bad for bikes and pedestrians, a lot of expense, and doesn't provide much more than a bus.

You should have watched this video: https://youtu.be/sEON08d76oE?t=112 it nicely explains the importance of things like tram rails, and keeping a potato in your pants.

Learning to ride a bike and learning to ride one on public roads with traffic are two different skills.

Dumbest comment I've read in a while here. Most Americans can't seem to "master" bike riding and so they all need to wear helmets. The Dutch don't and aren't the world capital of TBIs.

Dumbest comment I've read in a while here. (high five, it works both ways).

The Dutch have a bicycle culture and bicycle friendly streets where cars are outnumbered and don't despise cyclists in the manner of Sydney, Australia or Mean City, USA.

The Dutch also live in a flat country and don't extreme cycle down the side of Big Sur, etc either.