Underneath the gaudy red roses, stuffed teddy bears clutching tacky velvet hearts, and eye-wateringly expensive weekend getaways, Valentine's Day is a wonderful chance to celebrate love.
And to mark 14 February, here are five things you might not know about love and sex.
Chocolate contains phenylethylamine, a chemical that causes the release of dopamine and norepinephrine, the key hormones that help us fall in love.
It only takes between 90 seconds and four minutes to decide if you fancy someone, and 55 per cent of attraction is based on body language alone.
Only three per cent of mammals mate for life. Animals that do find a lifelong partner include gibbons, swans, wolves, albatrosses, penguins, eagles and termites.
Simply looking at a photo of the one you love, or even thinking about them, increases levels of oxytocin, the body’s natural painkiller.
1/30 Earth Day
Google celebrates Earth Day 2016
2/30 Ravi Shankar
Google marks Pandit Ravi Shankar's 96th birthday
3/30 Olympic Games in 1896
Google are celebrates the 120th anniversary of the modern Olympic Games in 1896
4/30 World Twenty20 final
Google celebrates the 2016 World Twenty20 cricket final between the West Indies and England with a doodle
5/30 William Morris
Google celebrates William Morris' 182 birthday with a doodle showcasing his most famous designs
6/30 St Patrick's Day
17 March 2016: St Patrick's Day
7/30 Caroline Herschel's 266th birthday
Caroline Herschel discovered eight comets and comprehensively catalogued the stars
8/30 Clara Rockmore's 105th birthday
Clara Rockmore was a pioneer of the Theremin musical instrument
9/30 International Women's Day
#OneDayIWill video marks International Woman's Day on 8 March, 2016
10/30 St David's Day 2016
Google marks St David's Day 2016 with a doodle
11/30 Leap Year
Google celebrates Leap Day 2016, February 28
12/30 Lantern Festival 2016
Google celebrates the last day of the Chinese New Year celebrations with a doodle of the Lantern Festival
13/30 Stethoscope Inventor, René Laennec
Google celebrate's René Laennec's 235th birthday
14/30 Valentine's Day 2016
Google celebrates Valentine's Day with a romantic Doodle
15/30 Dmitri Mendeleev
Google celebrate Dmitri Mendeleev's 182nd birthday
16/30 "The televisor" demonstartion
Google Doodle celebrates 90 years since the first demonstration of television or "the televisor" to the public
17/30 Professor Scoville
Google marks Professor Scoville’s 151st birthday
18/30 Sophie Taeuber-Arp
Google marks Sophie Taeuber-Arp's 127th birthday
19/30 Charles Perrault
Google celebrates author Charles Perrault's 388th birthday
20/30 Mountain of Butterflies discovery
Google celebrates the 41st anniversary of the discovery of the Mountain of Butterflies
21/30 Winter Solstice
Google celebrate the Winter Solstice 2015
22/30 St Andrew's Day 2015
Google marks St Andrew's Day 2015 with doodle featuring Scotland's flag and Loch Ness monster
23/30 41st anniversary of the discovery of 'Lucy'
Google marks the 41st anniversary of the discovery of 'Lucy', the name given to a collection of fossilised bones that once made up the skeleton of a hominid from the Australopithecus afarensis species, who lived in Ethiopia 3.2 million years ago
24/30 George Boole's 200th birthday
The Google Doodle on 2nd November to mark George Boole's contribution to science
25/30 Halloween 2015
Google celebrates Halloween 2015 using an interactive doodle game "Global Candy Cup"
26/30 Prague Astronomical Clock
Google celebrates the 605th anniversary of the Prague Astronomical Clock, one of the oldest functioning timepieces in the world
27/30 Autumnal Equinox
Google marks the autumnal equinox on 23 September 2015
28/30 The first electric traffic stop
Google marks the 101st anniversary of the first traffic signal system
29/30 New Horizons Pluto flyby
Google marks the Nasa probe's fly-past of Pluto on 14 July 2015
30/30 Father's Day 2015
Google marks Father's Day with an animated Doodle
Broken Heart Syndrome
Also called stress-induced cardiomyopathy, it is caused by an emotionally stressful event, such as a break-up, and causes sudden intense chest pain.
Jo Stas writes for How It Works Magazine. Follow the magazine on Twitter: