Lyric discussion by Acaeris 

Cover art for Lost lyrics by Within Temptation

In the context of the accompanying comic, this seems to be a song about the character Janyce and her hunt for her daughter Rorey.

My Interpretation

@Acaeris

Actually I'd argue that it is more about Sinead.

One of the consequences of the deal she made with Mother Maiden is that the memories of who you once were will fade with time the longer the person goes on fighting for redemption. Sinead is lamenting the fact she is losing memories of her old life and who she once was and is trying to hold onto those memories.