It's hard to describe exactly what was so unpleasant about it for me, but there's some element of time perception involved...it was as though my memories of dreams were encoded on the same track as my waking memories, and my days were missing the "pause between songs" so to speak.
Thankfully, at least for me, this is an effect that goes away quickly after I stop keeping a dream journal. I have had a similar effect when stressed/overworked, though, where I start dreaming in code. That's terrible.