My user preferences are gone after restart
I believe somehow my external drive was momentarily disconnected and after I restarted it was like a brand new computer.

I restored from my last time machine backup and everything was back to normal except....my external drive was missing from the last time machine backup.

Time machine then backed up my entire external drive again.

It seems all is well now.

The moral to the story.....don't go without time machine or some other backup scheme.