There are more exercises like this, unfortunately. Continuously tricks me as well.
To Dave Driesen: Yeah, I agree. In American English, we never say "the neighbor", it's always relative to someone else. "His neighbor", "my neighbor", "your neighbor" are all completely normal. When you say "the neighbor", you're implying that the neighbor in question could be halfway across the continent or even the world. If you don't have something relative to it, most people have no idea what you're talking about.
So... takeaway message? Reference points are good. And also DL's still in beta. There are bound to be possible answers and mistakes here and there.
Most people being people you know? This sentence is common place in my experience. Imagine you and I live in the same house and thus have a shared neighbour. Maybe it is our only neighbour, or maybe we were recently discussing this neighbour. Maybe his name is James.
You are angry I put certain adornmant in the garden that may or may not be offensive to our neighbour. You say "Don't you care what James will say when he sees this?"
And I roll my eyes at you and reply "No, I wasn't thinking about the neighbour."
Replace neighbour with another common noun and you might see how normal it is.
"Don't tell the boss!" Vs "Don't tell our boss"
Replace neighbour with a proper noun and you have a problem.
"No, I don't think about the neighbors." for essentially the same reason that Dave put "my neighbor," the sentence is unnatural in detect translation. The thing is Dave's "No, I don't think about my neighbor." is different in connotation than my "No, I don't think about the neighbors." and I am wondering where the range of "The guy next door can starve for all I care," and "I will not be swayed by the opinion of those around me," the Russian sentence falls?