Donald Trump has a MAJOR Walter Mitty complex

The latest example: His pledge that had he been outside Stoneman Douglas High School 12 days ago, he would have rushed in to stop the shooter, who murdered 17 people.

"You don't know until you test it, but I think, I really believe I'd run in there, even if I didn't have a weapon, and I think most of the people in this room would have done that too," Trump said at a meeting of the nation's governors in Washington on Monday.

Obviously, as Trump says, "you don't know until you test it." As in: None of us can know whether, put in a situation like security guard Scot Peterson during the shooting spree earlier this week, we would have rushed into the building to try to save lives. Peterson remained outside school for several minutes, and inside the shooter fired and fired. (Referring to Peterson and other Broward County Sheriff's deputies, the President said they "weren't exactly Medal of Honor winners," adding: "The way they performed was really a disgrace.")

But even as the President is acknowledging you can't ever know how you would react in a situation like the one in Parkland, Trump is also making the case that he knows that he would have rushed in -- armed or not! -- to save kids' lives.

The truth is we have no idea how Trump would have reacted. But, as his critics were quick to point out, his past comments on his tolerance for blood would not immediately suggest he would be someone sprinting into an active shooter situation.

In a 2008 interview with radio host Howard Stern, Trump recounted this story:

"So what happens is, this guy falls off right on his face, hits his head, and I thought he died. And you know what I did? I said, 'Oh my God, that's disgusting,' and I turned away," said Trump. "I couldn't, you know, he was right in front of me and I turned away. I didn't want to touch him ... he's bleeding all over the place, I felt terrible. You know, beautiful marble floor, didn't look like it. It changed color. Became very red. And you have this poor guy, 80 years old, laying on the floor unconscious, and all the rich people are turning away. 'Oh my God! This is terrible! This is disgusting!' and you know, they're turning away. Nobody wants to help the guy. His wife is screaming---she's sitting right next to him, and she's screaming."

In that same interview, Trump was even more succinct: "I'm not good for medical. In other words, if you cut your finger and there's blood pouring out, I'm gone."

Of course, a distaste for blood is not the same thing as a willingness or unwillingness to run into a dangerous situation.

But there is very little question that Trump has regularly re-written history or actively worked to shape events as they happen to cast himself in the best possible light. He is the real-life Walter Mitty. (Mitty was the creation of novelist James Thurber; he was a regular guy with a very active imagination in which he was always at the center of history -- and its hero.)

Remember that in the 1980s, Trump masqueraded as a young staffer within the Trump organization named "John Miller" who would talk up the sexual virility and appeal of "Mr. Trump."

This excerpt, from The Washington Post story revealing the existence of "Miller," is telling:

"'Actresses,' Miller said in the call to [People magazine's Sue] Carswell, 'just call to see if they can go out with him and things.' Madonna 'wanted to go out with him.' And Trump's alter ego boasted that in addition to living with [Marla] Maples, Trump had 'three other girlfriends.'"

During the 2016 campaign, Trump regularly touted his opposition to the war in Iraq from the start -- as alleged evidence that he had the judgment that his opponents in the Republican primary lacked at the time.

But his contemporaneous statements belie that initial opposition.

Trump impersonated a disabled reporter at a July 2016 campaign rally in Colorado but later tried to suggest that he wasn't mocking the journalist. (He was.)

The President repeatedly called special counsel Robert Mueller's investigation into Russia's attempted meddling in the 2016 election a "hoax" and a "partisan witch hunt." Of late, he has insisted he wasn't calling the special counsel probe a "hoax" but rather referring specifically to the idea that his campaign was colluding with the Russians.

There are lots (and lots) of other examples -- in Trump's business life and his far shorter time running for or serving in elected office. He has spent a lifetime subscribing to the idea that perception trumps -- ahem -- reality.

Again and again during his decades as a real estate developer -- especially including his multiple bankruptcies -- Trump would stare failure in the face, call it victory and move on. Whether he knew he was spinning or not, he would create a story that made him look as successful, desirable and tough as possible -- and that often did not comport with the established facts.

He is not the first politician to exaggerate -- or even lie -- about his own past.

Hillary Clinton recounted how she landed at a Bosnian airfield "under sniper fire" in 1996. But video of Clinton's arrival showed no such threat -- as she walked calmly off the plane. Then Connecticut Attorney General Richard Blumenthal was found to have hugely exaggerated his role in the Vietnam War -- including that he had ever set foot in the country -- during his 2010 Senate campaign. Al Gore invented the Internet. Richard Nixon didn't know anything about Watergate.

But Trump stands alone in terms of the sheer number of tales he tells about himself and his life. It's as though he is taking a red pencil to recorded history with every passing day -- and all his edits are aimed at a single goal: Ensuring that he is always the hero of the story. Every story.