drool retention

One of the disadvantages of having a beard is that, if you drool while you're sleeping, you're likely to wake up and find that your beard—like a sponge—has eagerly soaked up the drool coming out of your mouth.  Drooling while clean-shaven is bad enough, but drooling into a beard is a tactile and olfactory nightmare.  When you're clean-shaven, you can lift your head off the pillow to separate yourself from its soaked surface; when you've got a beard, the soak stays with you until you lumber into the bathroom and thoroughly wash the nastiness out.

On the bright side:  the more drool there is in your beard, the less there is on your pillow.

Sweet dreams.