What makes you say it was factual? According to the web site, it was purely fictional http://www.theterminal-themovie.com/main.html
http://www.straightdope.com/classics/a990820.html
Check it out - Iranian national Merhan Nasseri has been living in the Charles DeGaulle airport since 1988. He was a man without a country for a decade
Of course they would say the story is entirely fictional - why share credit? DreamWorks did pay Merhan Nasseri $250,000 for his story.
Regardless, I only brought it up as an example of someone who was unable to return to his home country, and therefore begame a stateless person. Just to show that it does happen, although it's rare.