Draco thought that had been the first time he'd looked at her and seen her as more than just Granger the swot – when she had said, "Oh... I'll be perfectly comfortable on your bed, Malfoy," and he had realised that Granger was female and actually rather attractive. He wonders now how he could have ever not noticed how pretty she was, how quietly, glowingly beautiful. But that was then, and this is now, and hindsight is always twenty/twenty and he can't blame himself for not seeing it sooner. He thinks it would have been easier if he'd never seen it.