Any kind of novelty or excitement drives up dopamine in the brain, and dopamine is associated with romantic love.

There were real reasons that you were attracted to somebody originally. The brain doesn't pick willy-nilly. Unless you part ways hating each other for some reason, that mechanism could get triggered again. You can literally fall in love again.

Women have a better sense of smell than men do, and it's even sharper in the middle of their menstrual cycle, when estrogen levels peak and women are more likely to be deciding whether a man's attractive.

Women like signs of money and education - things that indicate that not only is this guy going to have some resources, but he's also willing to share them.

Despite the myth that men are less committed, they are predisposed to desire marriage.

The Great Depression of the 1930s saw more American unmarried women working from nine to five, mostly in repetitive, boring, subordinate, dead-end jobs. But the number of working women doubled between 1870 and 1940. During World War II it doubled once again.

The only people you and I are likely to know in common are people in the news - politicians, journalists and celebrities.