Alpha!Poe and Omega!Finn decide to try for a baby. As the pregnancy progresses, Finn can't help but think the whole thing feels familiar. Pregnancy isn't as foreign a sensation as it should be. As time passes, he finally starts to remember.

AKA: Stormtroops aren't just raised from birth, they're bred from Troopers with the right genetic markers and parents are "reconditioned" to forget or feel no emotional attachment.