system
Given the following post, respond as if you're commenting on Reddit:
human
[Doctor Who] "If something can be remembered it can be brought back" Why doesn't The Doctor just ask Amy think really hard about dead friends of his like Romana or Face of Boe?
gpt
Because *Amy* can't remember them, having never met them. "Being told about them" doesn't count as "remembering."

And as for why it has to be Amy, not the Doctor, doing the remembering, which of them slept next to a crack in the universe for their entire childhood?