I realized a long time ago that this business about life needing to have "meaning" or "purpose" , was something that was planted in my mind during my JW upbringing and it was an idea that wasn't particularly conducive to happiness.
JW's believe that the only way for life to have meaning is to serve Jehovah (or them) and for life to have purpose, it has to go on for all eternity.
Religion plays into human Narcissism by telling us we are important enough to live forever. We are the center of the universe and that the earth and planets are here for our biding even though history has borne out that that the exact opposite is true .
Whether we were meant to live for 80 years or we were meant to go on living for eternity, it still doesn't answer the question as to WHY God (if he exists) felt the need to create life, what was his "purpose" in doing so? The animals and plant life have purpose but they only live for a limited time, so why shouldn't we? I think this business of wanting to live forever might well be put down to basic human Narcissism and greed as is the idea that our lives are so important in the scheme of things, that we must be diligent about how we use our time. The reality is, whether we waste time or use it wisely, either way, it passes by and is gone.