Couples' personalities converge over time to make partners more and more similar.
235
A Korean man called Lee Jin-gyu fell in love with his large, huggable pillow and married it.
29
Sandy, an African Penguin, has been in 'love' with her keeper at the Nuremburg zoo since 1996.
34
You burn 26 calories in a one minute kiss.
605
Parents receive 1 out of every 5 Valentines.
20
Kissing releases masses of oxytocin, a "love potion" that helps couples bond and feel more attracted to each other.
13
Every year around 1 billion Valentine cards are sent. After Christmas it's a single largest seasonal card-sending occasion.
14
Brain scans show that people who view photos of a beloved experience an activation of the caudate - the part of the brain involving cravings.
103