Atlan liked the idea of increasing his base speed permanently. If he could harness a fraction of his speed when he used his Angel Wings, then he'd be able to catch Lizzie in a matter of seconds. She wouldn't even see a blur.
The problem lay in the fact that it was easier said than done. He understood the concept of pushing something past its limits.
It was just like pushing a very heavy box up a hill. Sure, it's hard to move the box and it would only get harder and harder as he went up, but at least he would know that he was progressing.
The task presented to him by Lizzie was like pushing a very heavy box up a hill, but he didn't even know where the box was. How could he start the arduous task of pushing the box up, when he couldn't even lay his eyes on it?
"I don't know how to do that," admitted Atlan.