Lennie covered his face with huge paws and bleated with terror. He cried, "Make ‘um stop, George." (3.248)
Here's Lennie with his "paws" again, and this time he's "bleating," like a lamb about to be slaughtered—which, in one reading, is exactly what happens. He's an innocent who gets killed to please the men in charge.
Lennie said, "George."
"I done another bad thing."
"It don't make no difference," George said, and he fell silent again. (6.34-37)
And there you have it: the most depressing lines of literature ever. Ish.
Lennie knows he messed up, but we're pretty sure he doesn't understand the extent to which he's been getting in the way of his and George's dreams. George is crushed (duh), but it sounds here like he's almost resigned to it, too. What do you think?