Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution.
In looking for someone to hire, you look for three qualities: integrity, intelligence, and energy. But the most important is integrity because if they don't have that, the other two qualities, intelligence and energy, are going to kill you.
Remembering that I'll be dead soon is the most important tool I've ever encountered to help me make the big choices in life. Because almost everything - all external expectations, all pride, all fear of embarrassment or failure - these things just fall away in the face of death, leaving only what is truly important.