Channeling Chuang Tzu

Ever get the feeling that you're not real?

I got that feeling today, and it's weird.  I don't really know what to make of it.  Really, a couple of hours ago, it hit, and, since then, I've had to work to remember that I'm not just someone's dream and my actions have consequences and stuff; I'm not just going to wake up and have it all go away.  (Although... I did do that a few weeks back.  That was AWFUL.)

Sound off.  Has that ever happened to you?  How did you shake it?