Steven Covey in The 8th Habit:
“…by making 4 simple assumptions in your life, you can immediately begin leading a more balanced, integrated powerful life…
(1) Assume you’ve had a heart attack, now live accordingly.
(2) Assume the half-life of your profession is 2 years, now prepare accordingly.
(3) Assume that everything you say about another they can overhear, now speak accordingly.
(4) Assume you have a one-on-one visit with your creator every quarter, now live accordingly.”
“Live as if you were to die tomorrow. Learn as if you were to live forever.”