The key to understanding love on Valentine's Day isn't Hallmark, it's the insula and the striatum

[youtube http://www.youtube.com/watch?v=OYfoGTIG7pY&w=600&h=315]

Lot of different theories on V-Day depending on where you are in the great relational roller coaster -- some love it, some hate it, some utterly indifferent towards it. (I'm married, but more the latter than anything else.) I thought it was interesting back in my mid-20s single days to chec…