Make your bed!

I never understood the concept of making your bed. I understand that it makes the room look neat and clean, and don't get me wrong, I like my decorative pillows as much as the next girl, but let's be honest; the concept of making your bed doesn't make a whole lot of sense. I make our bed when 1) I know ahead of time that people are coming over and will tour my house or 2) on the rare days that the whole house gets a thorough cleaning and the bed just doesn't look right unmade with a totally clean house. Would someone like to enlighten me on why making your bed is important? Because I'm pretty sure there are people out there that are anal about it, and I don't get it.