Jim Carrey fans have commended the actor for his improvisation skills in iconic Christmas film How The Grinch Stole Christmas. The actor, 61, is well-renowned for his portrayal of Dr Seuss' Grinch in the festive 2000 movie.

Needless to say, Carrey was miserable on set but received help from a wildly unlikely source: a CIA trainer. In his own words, the person who helped Carrey get through filming The Grinch was "trained to teach CIA operatives how to endure torture."