IANAL, but 99% sure that the situation in Germany is that you have to identify yourself (give name, birthday, (address?)), but you /don‘t/ have to carry (or show) your government issued ID at all times.
I figured it worked the same in the Netherlands, but from what I can tell it's true that you always need to carry it and you can get fined if you don't. So quite a bit more strict. That sucks.
https://de.m.wikibooks.org/wiki/Rechte_und_Pflichten_im_Umga... (German)
I always thought as well that there is “Ausweispflicht” (ID carrying obligatory) in Germany.