Ah, this is indeed not an added question. It is, in fact, the very same question, just phrased differently.

This riddle lies smack in the heart of your earlier comment. You wrote, "I only wanted to focuse, that automatically fabricating correlations by our brain all day long has grown so much into a habit, that we are not always aware, what our brain is doing at each moment. And that thinking totally logical would mean to put away all those correlations our brain is making, without we are aware of it." This describes exactly why this riddle is so tough for so many people. I will tell you this. Graduate math majors have more difficulty with this problem than even undergraduate engineering majors; a fact witnessed to by the near intuitive way that Oleg immediately saw where the problem is, even if he didn't quite nail it down.