Prospective flight attendants listen to their instructor during an etiquette training course at Indigo Airlines' Ifly training centre in Gurgaon on the outskirts of New Delhi November 18, 2014. (Photo by Adnan Abidi/Reuters)

Father Christmas arriving at the Arding and Hobbs store in Clapham Junction, London, 2nd November 1926. (Photo by H. F. Davis/Topical Press Agency/Getty Images)

Firework display from the top of the Sky Tower to welcome the New Year on January 1, 2015 in Auckland, New Zealand. (Photo by Dave Rowland/Getty Images)

A passenger without pants waits for the subway train during “The No Pants Subway Ride” in Mexico City January 11, 2015. The event, the fifth organized in Mexico, is an annual flash mob and occurs in different cities around the world, according to its organisers. (Photo by Edgard Garrido/Reuters)

A model applies lipstick backstage during the “We Love Flamenco” fashion show in the Andalusian capital of Seville January 14, 2015. The show will run until January 18. (Photo by Marcelo del Pozo/Reuters)

A swimmer competes during the UK Cold Water Swimming Championships at Tooting Bec Lido in south London January 24, 2015. (Photo by Luke MacGregor/Reuters)

Migrating starlings fly in formation near the southern Israeli town of Rahat February 2, 2015. The phenomenon, known as murmuration, is most common during the winter months. (Photo by Nir Elias/Reuters)

A model displays a creation for designer Andres Sarda's Fall/Winter 2015 collection, during the Mercedes-Benz Fashion Week in Madrid, February 7, 2015. (Photo by Javier Barbancho/Reuters)