thanks, starthrower

It's interesting how now that the depersonalization / derealization has gone away, I can't even remember what it felt like. I'm glad I wrote the OP while I was experiencing the sensations, because it's like a blank now. I remember that it was hard to get anything done, but I can't remember why it was hard. I even wonder if it was all only my imagination now.

I think the feeling is so alien, that it can only be experienced in the moment to appreciate. (But I suppose it is that way for all psychological experiences.)

My case is pretty mild as it goes. It is helpful to know that these symptoms have a name. I can imagine it would be difficult if it was more intense. I kept feeling like I had forgotten what I was thinking in the middle of something important. "What was I trying to think? What is wrong with me? Why am I sitting here and can't do anything? ..."

I'm glad it isn't all the time, because that would be difficult.