Sigmund Jähn: Socialism doesn't mean live behind a Wall. Socialism means reach the others and live with the others.
Denis: Eighth floor?
Alexander Kerner: Yup.
Denis: Elevator?
Alexander Kerner: Broken.
Denis: Shit.
Alexander Kerner: You can say that again.
Alexander Kerner: On the evening of October 7, 1989 several hundred people got together for some evening exercise and marched for the right to go for walks without the Berlin Wall getting in their way.
Alexander Kerner: The future lay in our hands. Uncertain, but promising.
Answer: According to IMDb, Sigmund Jähn gave permission to be featured in the movie, but refused to play himself. It was very difficult to find an actor who looked like Jähn and spoke his typical dialect but after filming had begun, 'Wolfgang Becker' chose a Swiss actor. He was given complex make-up and was dubbed by another actor who came from Jähn's home region, the Vogtland.