Quotes I'm hoping to paint on the walls of my classroom

OK, that title's slightly mendacious. I'm hoping students will paint quotes on the walls of my classroom - I'll help. I'd like a combination of quotes I choose, and quotes they choose. Here are the quotes I've thought of so far:

Who controls the past controls the future. Who controls the present controls the past.

-George Orwell, Nineteen Eighty-Four

 

History is that certainty produced at the point where the imperfections of memory meet the inadequacies of documentation.

-Julian Barnes, The Sense of an Ending

 

The best moments in reading are when you come across something - a thought, a feeling, a way of looking at things - which you had thought special and particular to you. And now, here it is, set down by someone else, a person you have never met, someone even who is long dead. And it is as if a hand has come out, and taken yours.

-Alan Bennett, The History Boys


Ever tried, ever failed, no matter. Try again. Fail again. Fail better. 
-Samuel Beckett, Worstward Ho

Always, an ever-finer form is waiting to be found through patient and sensitive trial and error [...] A concept is the result and comes at the end. 
-Peter Brook, The Quality of Mercy (he's talking about the rehearsal process, and coming up with a "concept" for a production.

Other ideas welcome!