Today it's very popular for everyone to have their own narrative. That's good if you're writing fiction, but not if you're writing history, and even in fiction there are limits. For example, you can't write: "Once, a long, long time ago, six o'clock this morning, three magicians entered the city gates, both of them wearing hats." That doesn't make sense: if it's long ago then it wasn't this morning; "three" and "both" don't go together.In non-fiction it's even more important to realize that although everyone is entitled to their own opinion – they're not entitled to their own facts: WWII didn't start in 1946, WWI didn't end in 1902, Americans didn't attack themselves at Pearl Harbor and the Nazis didn't conquer South Africa. If we cannot agree on the basic facts, we cannot have an intelligent discussion.I was recently reminded of this basic truth by seeing it trampled underfoot. My nephew from the U.S. was here on Birthright; now he's on a type of birthright organized by his cousins, my kids. Taking him to Jerusalem, we went for a walk on the Old City walls. There was a pleasant girl, from an Arab neighborhood in Jerusalem, sitting in the ticket room selling the tickets. She spoke a fair English and good Hebrew. I mentioned the burnt-out light rail stations in Arab neighborhoods that I had again seen that morning and asked if she thought if they would be rebuilt, to which she replied she thought not. My nephew was puzzled by the reference, so I explained superficially that two years ago, when there was a military operation in Gaza, there were riots in certain Arab neighborhoods of Jerusalem and some people burned the stations. I was careful to not say "the Arabs burned the stations", because I always try to avoid generalizations, which are often half or slanted truths.She looked at my nephew and said: the riots were because a boy was kidnapped and burned alive. I was embarrassed at having forgotten that. I turned to my nephew and explained about the three Israeli boys who were kidnapped and killed by Arabs who were affiliated with or inspired by Hamas, and some Jews (all are now in jail) retaliated by killing an innocent Arab teenager in a horrible manner in a terrible crime. She replied: "The Israelis were soldiers, whereas the Arab boy kidnapped was sixteen – no, fifteen and a half". Not wanting to either argue or lessen the crime of the murder of the Arab boy, I nevertheless corrected her by saying that the three kidnapped boys weren't soldiers."Oh no, what I say is fact: they were soldiers – that is fact", she insisted. I thought she was merely mistaken or confused, so I repeated: "No, two boys were in high school and the third was a yeshiva student."She merely turned to my nephew – after all, I was the incorrigible Israeli, whereas my nephew represented "world opinion" at that moment, so she appealed to him, saying with absolute, unshaken belief: "No! They were soldiers – that is a well-known fact".I looked at the girl, who seemed to be intelligent enough, and was astounded by the disinformation she accepted – and wanted the world to accept – as absolute fact: three soldiers, not teenage civilians. Implied in her vehemence, apparently, was that if the victims were soldiers – that's OK.Later at home I would recheck what I knew clearly to be true fact: Naftali Fraenkel was 16, Gilad Shayer was 16 – both still in high school, and Eyal Yifrach was 19 but was a yeshiva student – not a soldier. I checked on international websites – so no one could claim that the Israelis were making this up. That was later, but immediately then, I realized that this girl is absolutely certain, because she believes the brainwashing propaganda that she is being fed by Arab sources. I realized there was nothing I could say to the girl, so I just turned to my nephew and said in a voice that the girl could hear: "Now do you see why there won't be peace here in the near future?" With a false "narrative" it's impossible to reason. But I always have hope for the future, even if it's not nearby.