Most people use this phrase to mean get the most out of life while it lasts, with which I agree. I believe it has a deeper meaning, a spiritual side of the same coin type meaning. Living in an attitude of acceptance is key towards living in the peaceful state of serenity. This is the message of this oft quoted passage: "And acceptance is the answer to all my problems today. When I am disturbed, it is because I find some person, place, thing, or situation — some fact of my life — unacceptable to me, and I can find no serenity until I accept that person, place, thing, or situation as being exactly the way it is supposed to be at this moment. Nothing, absolutely nothing, happens in [the universe] by mistake. …unless I accept life on life’s terms, I cannot be happy. I need to concentrate not so much on what needs to be changed in the world as on what needs to be changed in me and my attitudes."

It is hard to accept something from the perspective of life is long. It is also hard to accept something disturbing from the perspective of making the most out of our short lives, yet, from the perspective of this lifetime will last another ___ years, while my soul has existed and will continue to exist for all of eternity and will have the option to reincarnate and live out new and excitingly challenging life cycles as many times as I wish, acceptance becomes a very easy spiritual path to enjoying this "life-is-short" in an attitude of gratitude. This is among the many "chicken soup for the soul" messages I shared yesterday in https://medium.com/technical-excellence/waxing-tanka-about-home-5344f8581e1a.