Answer:
The more you take, the more you leave behind.
i'm popular for Knuzlocks what am i
I'm the source of all emotion, but I'm caged in a white prison.
You can read it both ways, I wearอพ One way it's a number, reversed a snare.
I open wide and tight I shut, Sharp am I and paper-cut fingers too, so do take care, I'm good and bad, so best beware.
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?