In 2005, about a year after he received his pancreatic cancer diagnosis, Apple's then-CEO Steve Jobs told Stanford's graduating class that, for 33 years, he would look in the mirror every morning and ask himself, "If today were the last day of my life, would I want to do what I am about to do today?"

If the answer was "No" for too many days in a row, he says he know he needed to change something.

"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," Jobs explained. "Remembering that you are going to die is the best way I know to avoid the trap of thinking you have something to lose. You are already naked. There is no reason not to follow your heart."