Some were discussing on here earlier how contestants on TV quiz shows seem to have a lack of general knowledge. I've just watched tonight's The Chase and witnessed this:
Bradley Walsh: What barrier was Chuck Yeager the first to break?
Conestant: The Thames.
It is nerves, few years back a lad from work was on a tv quiz show think he answered one question. before they started filming the show they had a mock run and he had the highest points. They had a short break for a drink of tea/coffee then they started to film the show and he just froze.