Film Favourite Movie Quotes?

What are your favourite or most memorable quotes that you've heard from seeing a film? How has the quote in question impacted you, and why was it so memorable for you?

a cliché one is "Yesterday's history, tomorrow's a mystery, but today is a gift. That's why they call it the present." It's a really beautiful way to say to live in the now and don't worry too much about things that have happened or might happen. I try to live by it even if I am really bad at it, haha. The quote as I remember it is from Kung Fu Panda ;)