Every year around 1 billion Valentine cards are sent. After Christmas it's a single largest seasonal card-sending occasion.
14
Wearing red increases attraction.
30
Couples' personalities converge over time to make partners more and more similar.
235
In Korea, if you do not receive any gift on Valentine's day then all the singles go to Korean restaurants and eat black noodles to celebrate (or mourn) their single status.
27
Historically, sweat has been an active ingredient in perfume and love potions.
309
You burn 26 calories in a one minute kiss.
605
Kissing an infection-free partner is good for your teeth!
141
Falling in love raises levels of nerve growth in a person's brain for about a year and can improve their memory.
39