Surreality is what happens to you when your life just begins to get stranger and stranger for no apparent reason at all. Things that have been known to cause attacks of Surreality are:

Boredom
Overexposure to Reality
Insanity
Large amounts of mind-altering substances
and of course, Overactive Imagination.

Surreality is generally harmless, though it can become VERY annoying at times.