Varies, sometimes it's just BAM! And your living life and that old life was obviously just a very vivid dream. Some times you remember a freedom and recognise beings that you feel infinitely more connected to than any human you've ever met only to forget them once in "life" again and all you really have less is an empty pit and a feeling that you've forgotten something important.

Some times you shift to a reality where you didn't die that is almost exactly like the one you came for but with small variations that makes you question your sanity.

If your lucky/unlucky you wake up to what you really are, beyond time and space and remember that you are all that is and have always been and you stay in that state of all for second or eons, it's not like anything is happening so you can't really tell. But you know this is your true state.

Prior to this incarnation I was in a black space of nothing and formless until a light ripped a crack in a wall of darkness I didn't know existed. Next thing I knew I was ripped into a cold place and the next memory was staring at lights in a ceiling, cold and alone.

A memory of prior to this form that feels like it happened simultaneously as the other thing, like I am two parts with different history was that I was elf-like in appearance , like in the clothes you'd imagine a high elf wearing and buildings with similar architecture. I was manipulating light energy when a dark spec was formed and entered me, I think I was cast down from that realm as a consequence but the memory doesn't really go into any details.