The fear of deflation

I hear it a lot from economists. I guess they fear we will gain too much momentum on the downswing. Do they fear the mass bankruptcy of the states? No one is predicting the Big One, where Europe goes to war over monetary mismanagement. Dunno what the fear is, never been in a deflation. Right now CPI and PCE seem reasonably stable , from month to month. In fact, the inflationary environment seems ideal, I wish we could keep it.