I agree with Dwayne.
If you look on Erowid's /Plants and Drugs/Full Substance List page for experiences by substance, it has a quote at the top which says: "You cannot deny the experiences of others".
I will say this though: this thread cuts pretty close to the recent discussion on Shulgin's ++++ experiences. Some of the trouble with the arguements invovle definition of terms. However, we are talking about a felt experience, and theretofore everyone's experience has to be taken as valid, or else there is really no basis for discussion.
I might say that the psychedelic experience cannot be quantified in terms of increments such as +1, +2, +3, +4 (even though the scale was used primarily for Shulgin's inital bioassays). The +4 experience could be said to be equivalent to that described by some people as ego-loss, since by it's very definition as transcendental we cannot know the state of the subject's ego during the time of the experience. There is also no reason to believe that the subject loses awareness during the experience and has to piece it back together afterwards. The autonomic functions seem, to an observer, to be functioning as normal, as do other brain functions, meaning that there is still a 'you' somewhere inside the organism keeping you alive. Complete ego-death would literally mean death.
But I will also add that, given a consensus agreement on the 'idea' of ego as a sense of compartmentalized self-ness, with boundaries between 'Me', 'I', 'You, and 'Things', it should be obvious that a state of ego-loss is simply a "loss" of those boundaries; a state of empathogenic and divine one-ness with all that is, based upon the concept of dependent-arising, or all phenomena entangled in causality, with phenomena which we call 'things' being divine emanations.
As it pertains to memory, we have no way of knowing when or how our daily experiences are remembered - simply that we receive them with a mechanism called the body, quantize the emanations in to transmutable thought phenomena, and then manifest (or broadcast/emanate our own interpretations).
Maybe.