'X' became symbolic for a kiss because in the middle ages when alot of people were illiterate and they used to sign documents with an X and then kiss it for sincerity.
255
Every year around 1 billion Valentine cards are sent. After Christmas it's a single largest seasonal card-sending occasion.
14
When you are looking at someone you love, your pupils dilate, they do the same when you are looking at someone you hate.
1k
Kissing an infection-free partner is good for your teeth!
141
Historically, sweat has been an active ingredient in perfume and love potions.
309
According to the New York Times, a study conducted during the 1980's found that men who kiss their wives before leaving for work live longer, get into fewer car accidents, and have a higher income than married men who don't.
14
Approximately 141 million Valentine's Day cards are exchanged worldwide every year.
104
Wearing red increases attraction.
30