I know during the traumatic event I had, I was disassociated...but yeah I experience it fairly often since that but yeah it can especially happen if I start talking about the PTSD and trauma and getting into more detail and such, like in a recent therapy meeting I was trying to explain something about it and just thinking about it that much was really stressful and I was anxious feeling...then when I left the therapy office I felt totally out of it...and sort of a floating feeling so sort of like a 'high' but without all the pleasantries.

But yeah I think the mind causes that as a defense mechanism so in a sense it is your brain trying to provide relief from the overwhelming stress...of course it can be rather debilitating if you are trying to do something involving coordination for instance and is just a rather uncomfortable feeling at least to me.