Every time a article like this is posted I'm just flabbergasted at the fact that 'looking behind you before actually opening a door' is such a foreign concept to Americans.
There's really a 40% failure rate? That's insane given how easy it is to pass the test.
https://www.kba.de/DE/Statistik/Kraftfahrer/Fahrerlaubnisse/...
[1] I actually do. Maybe it'll be me someday. But for the sake of argument let's pretend.