Poll: Which explanation of how wizards & walkers use mana is the best:
1) Pre-revisionist: Wizards carry small tokens from lands they visit with them to serve as a conduit. Using mana from another plane is visible to other walkers.
2) Ice Age Trilogy: Memories form a connection to the land, and change is the source of mana.
3) Modern: Narrative convenience, mostly seem to draw from the plane you are on, kind of an ambient energy.