U.S. Democratic presidential candidate Hillary Clinton listens as Vietnam War veteran Bob Hannan speaks during a veterans round table discussion with the Truman National Security Project at the VFW Hall in Derry, N.H., on Nov. 10. (Brian Snyder/Reuters)

Hillary Clinton tells a story of how she tried to join the Marines in 1975 but was rejected because she was too old. The problem? The story may not be totally true.

As The Post's Fact Checker illustrates in a column dedicated to Clinton's Marine claim Thursday, there's little reason to believe that she -- already a very prominent person -- would suddenly attempt to join the military.

The Fact Checker doesn't say Clinton is lying -- and notes that several of her friends have, in the past, vaguely corroborated Clinton's recounting of her interest in the Marines. But it awards Clinton Two Pinnocchios for the claim, meaning: "Significant omissions and/or exaggerations. Some factual error may be involved but not necessarily. A politician can create a false, misleading impression by playing with words and using legalistic language that means little to ordinary people."

This isn't the first time that Clinton might have been caught exaggerating the details of her past life. In a speech in Iraq in 2008, Clinton recounted landing in Bosnia under sniper fire. "There was supposed to be some kind of a greeting ceremony at the airport, but instead we just ran with our heads down to get into the vehicles to get to our base," she said.

Videos unearthed of Clinton's arrival showed a very different story -- a calm scene without any obvious danger. Clinton recanted a week after giving the speech, saying that she had misspoken. But she was still whacked for exaggeration by then-candidate Barack Obama's campaign -- an Obama spokesman at the time cited "a growing list of instances in which Senator Clinton has exaggerated her role in foreign and domestic policy-making" -- and given a "pants on fire" rating for the claim by the fact-checking service PolitiFact.

In a 2008 speech in Iraq, Hillary Clinton said she landed in Bosnia under heavy fire. But video of the landing shows otherwise. (AP)

Compare Clinton's exaggerations -- both the one we are sure of (Bosnia) and the one where recollections are hazy (Marines) -- to the spate of recent stories about GOP front-runner Ben Carson and his recounting of his past.  It seems, at a minimum, that Carson misremembered/exaggerated the idea that he met with Gen. William Westmoreland and/or was offered a "full scholarship" to attend West Point. And his stories of a violent youth highlighted by a terrible temper, while not proven entirely untrue, have had some doubt cast on them by reporting done by CNN in which his childhood acquaintances seemed to remember things differently.

On their face, the extent of the exaggerations at issue seem very similar. And yet, Republicans note, Carson is being cast by the media as a fraud while Clinton is being given a pass. Liberal bias, they scream.

[WATCH: Why Ben Carson's pyramid comment won't hurt him]

Maybe. But I think it's less bias for political reasons and more bias for new news stories.

Carson is a totally new political commodity. He had never run for anything before this race. His rise to the top of the field has been heavily reliant on his personal story -- going from abject poverty in Detroit to become one of the world's most renowned brain surgeons. The Ben Carson Story is not one that most people are already familiar with. What's happening now is that getting-to-know-you moment with voters. There's a freshness tied to the Carson story, then -- a freshness that, when linked to his status as the Republican front-runner, makes the vetting of his story have a clear news peg.

Clinton, on the other hand, is, well, not new to the political scene. And  her story isn't either. While not everyone is familiar with all of the particulars of the Bosnia incident or her applying for the Marines (or not), there is some sense that she is a known commodity for voters. Hence, no news peg. And less coverage. (Although it's worth noting that the reason I am writing this post at all is because of a fact check by my news organization of a claim made by Clinton on the campaign trail.)

I also think there's a deeper debate in here about politicians -- who they are and what we require of them.

First, who they are. They are human. Like us. That's obvious, sort of, but very important to remember in this context. All of us -- me included -- like to tell the story of our life in ways that make us look as good/noble/selfless/cool as possible. Small exaggerations can turn into big ones without you even realizing it. Sometimes the story you tell of your life is so convincing -- and close enough to what really happened -- that  once you repeat it enough times, you aren't so sure it's not entirely, perfectly accurate.

Politicians are pleasers in an industry that loves to please. They want people to both admire them and relate to them -- and the way to do that, usually, is by finding some sort of shared experience. In doing that, details can get obscured or elided.  A story a pol tells which is close to the truth if not the perfect truth, might get such a great response that they just keep telling it. And each time, the retelling the story drifts a little further from the original episode. It happens.

Now to what we expect from politicians. We expect them to not give in to that very human tendency to tell the story in a way that makes them look just a little bit better or braver. And we expect them to have absolutely perfect recall of everything they have ever said or done in their lives -- a trait that, speaking for myself, I lack.  Ask yourself this: Do you remember things you said 20 years ago? And, even if you do, could you recount the specifics of those conversations -- what was said, where it was said, who all was in the room, etc.? I think for most of us, that would be a stretch.

That is not to excuse politicians whose little white lies are more than, well, little white lies. In Clinton's case, it seems unlikely to me that she would simply misremember whether or not she was being fired on when she landed in Bosnia. In Carson's, I can see how a conversation from decades ago might be misinterpreted, although conflating a "you should apply here" to "here is a full scholarship" seems like a bit of a stretch to me. (I had a very nice conversation with a Stanford alum when I applied there; I did not take that very nice conversation as proof that the rejection letter the university sent me should be ignored.)

If nothing new comes out about irregularities in the way Carson has painted his past, my guess is this is a blip on the radar of his campaign -- nothing more. Ditto Clinton; she weathered the Bosnia revelation during the 2008 campaign and seems likely to me to have little trouble handling this Marines story, too.

The broader point here is how our expectations for politicians work -- and whether those expectations are realistic or not. I think, in the main, they aren't.