The idea of "awakening as a senshi" - remembering their past life - comes up in both the anime and manga versions of Sailor Moon. However, in PGSM, it's not just Luna who won't tell anyone anything (or doesn't know herself), but Sailor Venus as well.

The gradual detachment of Usagi, Ami, Rei and Makoto from each other, over the course of several episodes, is something very unlike both the anime and manga. In fact, it's things like this that are PGSM's biggest strengths over the other versions. The manga barely devoted any time to character-based stories that didn't directly related to the "Fighting Evil" plot, and while the anime had lots of episodes where the girls disagreed, everything was always resolved by the end of the episode. However, PGSM can have this kind of thing happen gradually, to the point that I didn't realise quite how little time they were spending together until it became as big a deal as in this episode and the next few.

I apologise if the above was ramble that made no sense. I'm kind of reaching for things to write about here.