Just observing

One thing that reportedly happened when the Buddha, sitting under the Bodhi tree, achieved enlightenment was that in the second stage of his meditation, he became able to access memories of all his past lives.  It is interesting because in his other teachings he doesn't much refer to this -- just observing.

The problem here is that if you look closely this ability would seem to remove the founding principle of Buddhism, that to live is to suffer, since the suffering spoken of is not pain or nausea or even frustration, but the realization that we are nothing, that we live and die and even though we are reborn what is reborn is not really us but a new entity with its own experiences and genes.

Memories are a function of physical brain tissue.  Damage it or let it suffer disease and memories go away, as they do with death and rebirth, if this actually happens.

To be sure, we also die and are reborn from moment to moment.  What gives the illusion of self is that we have access to memories, fallible though they may be, of our previous current life.

The Buddha's experience suggests that there is another place where memories are also maintained -- a non-physical place -- and he was able to access that and perhaps transfer information to his living brain.

The implication I get is that once one has achieved enlightenment one no longer needs to stop the rebirth cycle.  One's total insignificance becomes something else and we no longer suffer in this way.  Then, if we work on making the Earth a nice place, all suffering can be abolished, but regardless the main suffering is dealt with.

It may be that enlightenment doesn't always bring with it this ability, in which case entering bliss would seem to still be the way to go.  At any rate, there don't seem to be many around carrying with them the accumulated knowledge and wisdom of millions of past lives.