What is important about the title? What is the famous reference? Was the title misleading?

ohn Steinbeck takes the title of this novella from the poem "To a Mouse [on turning her up in her nest with the plough]," written by Scottish poet Robert Burns in 1785. In the poem, the speaker has accidentally turned up a mouse’s nest with his plough, and takes the opportunity to wonder at man’s separation from the world of animals. Still, the speaker thinks both mice and men suffer from being mortal, so no matter how different "thinking men" and "unthinking animals" seem, they really aren’t that different after all – everybody suffers in the end. This thought isn’t too far off from what ends up happening to our "thinking man" (George) and his "unthinking friend" (Lennie).

Most critics talking about Steinbeck point you to the seventh verse of the poem:

But, Mousie, thou art no thy lane [alone]

In proving foresight may be vain:

The best-laid schemes o' mice an' men

Gang aft agley, [often go awry]

An' lea'e us nought [leave us nothing] but grief an' pain,

For promised joy.

I don't think there is anything "misleading" about the title when taken in the above context.