Globe and Mail –

First, the scientific reason:

As you may know, falling in love involves feelings of exhilaration, intense passion, and euphoria, especially if the loved one reciprocates the passion. Of course, if the loved one doesn’t feel the same way, these feelings morph into desperation and heartbreak. But let’s not go there today.

Back to falling in love. Our energy skyrockets, we have heightened powers of concentration and persistent thoughts about the object of our affection. During this state, our brains show heightened activity in areas that are rich in dopamine if scanned using functional magnetic resonance imaging (fMRI).

Dopamine is a neurotransmitter associated with natural reward systems, those brain circuits that give us a sense of pleasure when we engage in behaviours related to survival, like eating, drinking and having sex. It is also the system that gets hijacked in addictions to various drugs. When we are in love our brain is in a pleasure state not unlike being high on drugs like cocaine. There are other neurobiological alterations that occur with passionate love, including an increase in certain hormones involved in the stress response (cortisol) and those implicated in bonding with your mate (vasopressin and oxytocin). This brain cocktail leaves us in a hypomanic-like condition. As with hypomania – a state of elevated mood, energy and activity that occurs with bipolar disorder – the need for sleep may be reduced when we are intensely in love. We spend plenty of time trying to be with our beloved, and we spend less time asleep.

Very few researchers have directly asked people who are in love about their sleep. A notable exception is Professor Serge Brand of the Psychiatric University Clinics at the University of Basel in Switzerland. He and his colleagues studied young people who were in “early-stage intense romantic love.”

Their study, published in the Journal of Adolescent Health in 2007, found that intensely in-love adolescents reported having shorter sleep (by about one hour) than their not-in-love counterparts. Furthermore, sleep was shortest in those who were most obsessively distracted by thoughts of their loved one.

And for the real reason, just click the below image…

(In case it doesn’t go there automatically, advance the video to 17:20.)

Yep, enough said… 🙂