Is it normal to see
and hear a thunder like phenomenon in your head all of a sudden? Not in the sense you visualize other things in your mind. I had no will over it. It just happened. A flashing light that "fills" your head accompanied with a very loud explosion type sound. It scared the shit out of me.
To add to that there were some incidents in the past where i could hear a guy in my head screaming my name. Both experiences lasted for a blink of a an eye.