How does our perception of ourselves change?

[anagogy]

So, does our perception of ourselves change as we progress back to the source?
I guess I'm wondering if I will remember all of this, or will it just blend itself in with all of my experiences in other lives?

To kind of parrot what others have said, the answer is a mixture of both. The creator knows all aspects of the creation, including all those experiences that culminate in the totality of your individuality, and it knows them in exquisitely precise detail. But they will not be held in any greater or lesser esteem than any other experiences in the one infinite creation. All will be seen as another perfect and unique facet of the creator.

More than that. What role does our Higher Self play?
I understand we are an extension of the Source, or the Creator which is the core of all life.
In the same way, Is our Higher Self the core of our individualized being, and are our many lives an extension of that core?

That would be an accurate statement from my perspective. You could almost conceptualize the "higher self" as the embodiment of the inner descending prana or life force from the creator, radiating downwards to meet the upward spiraling prana that is representative of your present 3rd density conscious self. It is the time/space analog to your space/time self -- a mirror image of sorts (though let us not forget that the reflection in the mirror is an inverted image -- subtleties are important). Where the upward and downward spiraling prana meet represents your current density level of consciousness and the area of thought that your spiritual lessons are being offered from.

The higher self is the apex of your individuality -- the greatest balance of self, before self becomes melded with all other selves. If your trip through the densities were a kind of maze with many twisting, winding, labyrinthine corridors, the higher self would be the end point on the maze. In other-words, no matter what path you take through the maze, whatever choices you make, you will cross through the state of being that is represented by your higher self at some point, hence why Ra describes the higher self as a map in which the destination is known.

It is something of a personal intermediary between the personal self, and the impersonal divine god self.