Yeah, Douglas Adams! I'm such a geek, I love Hitchiker's Guide!
Here's another law.
Kelly and Jocelyn's Law of Girlfriend Gravity
Girlfriend Gravity is a force which holds one down to the spot where one's girlfriend has spent the most time. If you're lucky, it's the bed.
The amount of Girlfriend Gravity is directly relative to the amount of appeal the girlfriend possesses added to the total amount of time the girlfriend spent in that location.
Girlfriend Gravity will dissipate at a rate proportional to the amount of time the girlfriend spent in the affected area.
For example: Jocelyn slept in the bed for eight hours. I couldn't make myself leave the bed for 4hrs and would've felt inclined to stay in the bed for 4 more hours had she not dragged me out.
It is generally believed that Boyfriend Gravity works the same way, but there is no conclusive evidence at this time that Boyfriend Gravity exists. Further studies are planned at an undisclosed time.