An anecdote about Neil Armstrong circulates the Internet every now and then. Almost as much, in fact, as the video of Buzz Aldrin dealing with a Moon conspiracy theorist "like a gangster".

The anecdote attributed to author Neil Gaiman, usually posted as a Tumblr screenshot, goes like this. Gaiman was at a gathering of artists, scientists, writers, and other notable celebrities. While at the gathering – which lasted several days – he felt like he hadn't achieved enough to qualify his place among these other greats.

"I felt that at any moment they would realise that I didn’t qualify to be there, among these people who had really done things."

The feeling is what's commonly known as "impostor syndrome". Though not considered a diagnosable condition (like other syndromes), the term was first coined by psychologists Pauline Rose Clance and Suzanne Imes in 1978. 

"The term impostor phenomenon is used to designate an internal experience of intellectual phonies, which appears to be particularly prevalent and intense among a select sample of high achieving women," the psychologists wrote in their paper.

"Numerous achievements, which one might expect to provide ample object evidence of superior intellectual functioning, do not appear to affect the impostor belief."

The syndrome is not based on external factors. Just because you feel like an impostor does not make you one. Gaiman, himself a highly respected author, felt it in spades at the gathering. Then, he met a fellow attendee, who put things into perspective.

"On my second or third night there, I was standing at the back of the hall, while a musical entertainment happened, and I started talking to a very nice, polite, elderly gentleman about several things, including our shared first name," Gaiman writes on his blog, where he confirms the anecdote to be true. 

"And then he pointed to the hall of people, and said words to the effect of, 'I just look at all these people, and I think, what the heck am I doing here? They’ve made amazing things. I just went where I was sent.'

And I said, 'Yes. But you were the first man on the moon. I think that counts for something.'”

Yes, even the first person – after an incredibly lengthy and arduous selection process – to set a foot on the actual Moon feels this way. After the encounter, Gaiman writes that he felt much better.

"Because if Neil Armstrong felt like an impostor, maybe everyone did. Maybe there weren’t any grown-ups, only people who had worked hard and also got lucky and were slightly out of their depth, all of us doing the best job we could, which is all we can really hope for."