Albert Einstein. Did you know "he was visiting the United States when Adolf Hitler came to power in 1933, and did not go back to Germany, where he had been a professor at the Berlin Academy of Sciences"? (Wikipedia) Can you imagine the consequences if he HAD returned to the Third Reich?
Inspirational quote. I like a lot of Einstein's quotes, even if they're cheesy for a scientist to be using, but they really emphasize creativity and imagination as being a very important tool for advances in science. While textbook knowledge is necessary to have, without creative ideas and questions you won't get very far.
There's never enough time. But time is so relative, therefore we must make the most of it. Because when it's time to say goodbye, our life begins once again and then, time is infinite. But it's the time we spend with certain people and things on this planet that make time seem short and never enough.