I suffer from epilepsy. I think that I may have had it as an infant but it came back when I was in my fifties. If you are epileptic, you can have two types of seizure - 'petit mal' or 'grand mal'. If you experience the latter type, you just lose consciousness and fall over (now I'm on medication, I occasionally lose consciousness but don't fall over - go figure!). But it is the former type of seizure which is most puzzling. Sometimes I find my mind sort of 'chasing-its-own-tail' trying to solve a non-existent puzzle but other times I have a sort of 'deja-vu' type of experience in which I visit another reality. This reality is very ordinary and mundane but its not the one I normally experience. Afterwards, I can't remember any details. During one of these experiences am I just recalling a chunk of my earlier life, having a waking dream or temporarily visiting another me in a parallel universe (probably not)? This is all down to neurons mis-firing in my brain but I do know what 'altered consciousness' feels like.