The riddle of "the two brothers"

was asked of me yesterday.  I was actually asked by a complete stranger in the supermarket queue. 

"Yes, I know the riddle and I know the answer which is generally given," I told him, "Why do you want to know?"

"My son asked me. I can't follow his logic."

  Most, if not all, of you will know the riddle. 

You are walking down a road towards your future. You come to a fork in the road and don't know which one to take. One will lead to happiness and a long life. The other will lead to unhappiness and an early death. There are twin brothers standing there to direct you. They are identical in every respect but one. One brother always tells the truth and the other brother never does.

You can ask just one question of one brother. What question do you ask?

In case there is someone reading this who wants to try and work it out for themselves I will not give you the answer.

I could also see why the man who asked me was confused. I was not the first person he had asked. He was getting confusing answers. Some people were saying it was not possible to answer the riddle. Others were telling him "it's simple".

It is not "simple" at all. It does require some thought. The answer can be reasonably straight forward but it can be more complex than that.

I wondered why it was bothering him so much. Did he simply not like to be puzzled by something his son had asked him? (In the course of the discussion we had once we passed through the queue his son turns out to be thirteen.)

No, it was not that. It turned out that one of his son's teachers had given the class a highly politically charged lesson on voting "yes" at the upcoming referendum. They were to go home and try to persuade their parents to vote yes by using the riddle as an example of what would happen if they voted no. 

I didn't follow the logic of this. It sounded illogical to me in fact. Like the father however I was much more concerned that the matter had even been raised in the classroom. Thirteen year old students are not old enough to vote. They may well be interested in politics, far more so than my generation was at their age, but they do not vote. Under no circumstances should their teachers be trying to indoctrinate them to influence their parents.