10 Saint Valentine's Day trifles. 

1. St. Valentine’s Day traces its roots to a Pagan festival - held on the ides of February - called 'Lupercalia', at which men stripped naked and smacked women's arses with whips as part of a fertility ceremony.*
2. Saint Valentine is the patron saint of lovers and engaged couples. He is also the patron saint of, amongst other things, epilepsy, plague and bee keepers.
3. The patron of love is Saint Anthony, whose day is celebrated on June 13th.
4. From the Victorian period to the early twentieth century, there was a craze for insulting greeting cards – called ‘Vinegar Valentines’. (In 1906, the Chicago post office refused to deliver 25,000 of them.)
5. Penicillin, a popular treatment for venereal diseases, was introduced to the world on Saint Valentine’s Day 1929.
6. According to the American greetings card company Hallmark, around 15% of women in the United States that received flowers for Valentine’s Day last year sent them to themselves.
7. The New England Confectionary Company sells more than 8 billion candy hearts (similar to the UK’s Lovehearts) a year – mostly on the run up to Valentine’s Day. In 2011, the company ‘retired’ the classic phrases ‘Hep Cat’ and ‘Fax me’, in favour of ‘Tweet me’ and ‘Text me’.
8. According to the US National Retail Federation survey, more than nine million pet owners bought Valentine’s Day gifts for their pets in 2013.
9. In Japan, where (due to a mistranslation) only females give out St. Valentine’s Day gifts, men can protect themselves against the shame and ignominy of receiving nothing with ‘Valentine’s Insurance’.
10. On February 14th last year, romantic Americans spent in excess of $14.7 billion on flowers. Similar to the GDP of Iceland.

*Or, according to  Wikipedia, ‘striking those they met with shaggy thongs’.