It’s all very sobering, but you’re alone, so don’t sweat getting emotional.
Here’s a tip: Start with a guided walking tour. Germany’s history is visible on almost every corner of Berlin, and getting quickly acquainted with its darker realities gives you a strong geographical and cultural foundation for the rest of your trip. Explore the Jewish District, see the site of the former SS & Gestapo Headquarters at the Topography of Terror Museum, and visit the Holocaust Memorial. It’s all very sobering, but you’re alone, so don’t sweat getting emotional. Walk along the East Side Gallery—the spectacularly painted remains of the Berlin Wall—and see the Brandenburg Gate at sunset. Berlin is where events you’ve read about in textbooks since you were 14 years old actually happened, and connecting dots will never be this compelling.