Dave has a level of persistence unmatched by most other cats. Really the only other worldly thing that can compete with Dave's persistence is the Java updater. Day after day, the goal is the same.
It is Dave's remarkable persistence that allows him to develop great napping techniques such as this one. It's not always easy, but Dave can work through times of frustration, because he knows his goal is comfort, and he won't stop until he achieves it.