Many Germans may have believed that the Gestapo were everywhere and listening, but they weren't. Your neighbour was your enemy.
I live and work in Switzerland (big surprise, see username), where there is a sizeable German workforce.
Now, I fully realise that the plural of "anecdote" isn't "data" - but this tallies with what a little older people around here tell me about growing up in the GDR.
I'm 36 myself, and the fall of the Berlin Wall is pretty much the first major world event I vaguely remember. But a lot of the people I work with have very vivid memories.
One of the most insane stories I've heard was from a now executive, about a decade older than myself (would have been a teen when the iron curtain fell), who will not place a call unless he's in an enclosed space.
When I asked him about this once, he explained how, when he was a child, his family would have had a telephone at home, which was, apparently, not the norm for everyone. And how the phone was wall mounted in the kitchen, and his mother used to make them close the window when it rang - because they lived on the ground floor and she was genuinely concerned about some Stasi informant eavesdropping and reporting the family.
This was truly gobsmacking! I'm not under-educated and I do know about the Stasi - but hearing from a colleague just how deeply this cut into the very basic habits of their lives made me shiver!