What are some iconic quotes that have stuck with you?

I was recently reading Julius Caesar when I come across the famous quote - "The fault, dear Brutus, is not in our stars, but in ourselves"

Another one that I like is from the poem, "The Road not Taken" by Robert Frost, which is- "Two roads diverged in a wood, and I— I took the one less traveled by, And that has made all the difference."

So what are some iconic quotes that you admire?