When we were newly married we shared an apartment with a Sri Lankan couple - one of the more difficult living arrangements I've had. Not for them being from another land, but the husband was a habitual liar. He was always spinning stories and then stories to support his stories. It completely baffled me that someone could be like that, but it was pretty dramatic (they had an arranged marriage - we felt very sorry for his poor wife).
Since then there has been quite a bit of work on Narcissistic Personality Disorder - or NPD for short. A few weeks ago a piece by Mark Singer - Marathon Man - appeared in The New Yorker. I was recommending it to someone as it is the best discussion about someone with NPD that I've seen and to my surprise it is posted outside of their paywall.
The article is about Kip Litton - a dentist who is taken to lying about his marathon performances and the runners who called him on it. It turns out marathon times of three hours or less are impressive and any runner remembers their best time - usually to the second or tenth of a second - for the rest of their lives. These folks work hard at their sport and lying is not tolerated - Singer's piece is largely about the online community of runners at letsrun.com that took Litton apart.
The same community came together to take apart Paul Ryan's marathon claim - most impressively it turns out.
Why would someone exaggerate themselves like that? In Ryan's case it isn't the first time. I suspect more than a few politicians have NPD and Representative Ryan seems to have a strong case of it.
All politicans stretch the truth here and there - some to a much greater extent than others. I'm guessing Romney made a very bad choice with Ryan - having someone with NPD at such a level is probably not very healthy.