Sleeping at a 45 degree angle (idea)

In the sci-fi TV show Babylon 5, the Minbari are said to sleep at an angle for a different reason: To them, lying down is something that you only do when you are dead.

So, lying on a typical flat bed would be akin to a human sleeping in a coffin. However, there are angsty goth and vampiric types who think it is cool to do such a thing.