Elusive memories?

I've been playing since mid June so a little over 6 months but recently realized I'm still missing two regular obtainable memories. I've still managed to collect 20 shards of the Rafayel one but the Zayne one has completely escaped me. I'm not sure I'll ever be able to get them at this point as the galaxy explorer is so random and it'll be further diluted with the upcoming addition of the new LI. Anyone else in this boat?