Men couldn't care less if your strands are perfectly styled and neat. In fact, he might like you more with some wildness or bedhead, since it shows you're carefree and relaxed.

You can get into a very fancy car and know everything about the engine, but when you drive in that car, you feel that rush. In the same way, I think the more you know about love, the more you can enjoy it. And knowing about your personality type, who you are and what kind of person you're dealing with gives you a great leg up.

There's all kinds of reasons that you fall in love with one person rather than another: Timing is important. Proximity is important. Mystery is important. You fall in love with somebody who's somewhat mysterious, in part because mystery elevates dopamine in the brain, probably pushes you over that threshold to fall in love.

Women are better at reading body language everywhere in the world. As a matter of fact, it's associated with the female hormone estrogen. Women are better at figuring out of tone of voice, reading your face and posture and gesture.

Your sweetheart calls you by another's name. His eyes linger too long on your best friend. He talks with excitement about a girl at work. And the fire catches. Jealousy - that sickening combination of possessiveness, suspicion, rage, and humiliation - can overtake your mind and threaten your very core as you contemplate your rival.

Romantic love is one of the most addictive substances on Earth.

Whether you're married or not, relationships - and the satisfaction tied to them - are extremely important for increasing men's and women's quality of life.