Sai thought he understood? Hadn't he been the one to tell Sasuke that he was trying to understand what bonds were in the first place? Sasuke restrained himself from making a disbelieving snort (he was too old for such immaturity) and focused instead on not getting hot water down his injured side as much as possible.

"It doesn't matter how tenacious they are," he said shortly. "Even the dumbest animals will learn to run if they're beaten often enough."

Implying that Naruto and Sakura were dumb animals, which wasn't quite true. Despite Sakura's book smarts, their learning curve was apparently even steeper than that of a typical animal.