If you work through a math problem with pen and paper or nand2tetris or nandgame.com then it becomes obvious that changing indexes into a register file (a.k.a.

If you work through a math problem with pen and paper or nand2tetris or nandgame.com then it becomes obvious that changing indexes into a register file (a.k.a. pointers) are way faster and easier than wires to move stuff around.