<p>In FORREST GUMP, Gump runs for 3 years and 2 months. In WITHNAIL AND I, Withnail drinks lighter fuel and survives apparently unharmed. In TWISTER, a tornado picks up a petrol tanker. In KEYSTONE HOTEL, a custard pie is teleported down a phone line. In DUMB AND DUMBER, a criminal is killed by a super-hot chilli. Hollywood is notorious for playing fast and loose with the laws of man and nature. But does it deserve its reputation for mangling rea...