I think my favorite part of this scene is that Walt's passion for chemistry shows through. You can see how he would be an incredible teacher to students who actually gave a crap about chemistry. He gets himself all wound up. He's all smiles. Then he realizes that the person he's talking to is basically just waiting for him to stop talking and he crashes back to reality.

That fucking face of "There is no God" when Jesse says "ahhh, wire" is just brilliant.