Well done, congrats! Kinda weird you gotta know stuff most Germans don't know to become German. I mean I think Helmut Kohl was in power when the wall fell but I guess Willi Brandt layed the ground work. But who signed something specific? Honestly no Idea even if I went to a German high school.
Tell me how you behave if you sit next to a stranger on a bus when a double seat becomes free and I'll tell you whether you've properly integrated lol