I often got wee bouts of "depersonalisation" even before I got ill. I always thought they were just normal. And another one where it feels really weird to think that I am me, absolutely and utterly alone inside this body, but that I'm observing it from outside. Completely different to "fog", and completely different to the strange one when I was on amitriptyline where I felt as if my feet were miles away from my head... I couldn't believe how far away there were when I looked down at them - enough to make me topple over!