That "What if you knew you were going to die" question
You've no doubt seen the question in many different forms. Sometimes it's, "What would you do if you learned you were going to die tomorrow?" Other times it's "What would you do if you knew you'd live a hundred years?" Some people try to pack the whole thing into one exhortation, "Live like you were going to die tomorrow, plan like you'd live forever." It's always bugged me.
I understand what the question is trying to get at. It's trying to get you to think about what's really important. If you only had a little time left, hopefully you'd spend it doing the things that really matter--connecting with family and friends, perhaps. Contrariwise, if you have vast amounts of time--enough to see a really big plan through to fruition--it frees you to think big. But neither version really works for me.
See, if I were going to die tomorrow, I'd probably do stupid stuff--the sort of fun stuff that I normally keep under strict limits because it has long-term negative consequences. If you're going to die before the negative consequences kick in, there's no need for limits. If I were going to die tomorrow I could pack a lot of pleasure into one day--but if a miracle treatment gave me one more day I'd probably make very different choices for that next "last" day. Maybe the question would work better if the time frame were, let's say, six weeks--short enough to focus the mind, but long enough that there's still value in moderation and thoughtful consideration. But, for me, it's not the right question.
The other one isn't either. If I knew I would live forever (or even just a very long time), I'm sure I'd take the long view on certain things--my investment portfolio, for example--but I'm also sure I'd be prone to some serious procrastination, knowing that I had the whole vast future to get around to doing whatever it was that I didn't feel like doing today.
For me, the issues these questions are supposed to help with are dealt with much better by thinking in terms of balance. Happiness doesn't come from packing each day with as much hedonistic pleasure as possible--although one day like that can be a lot of fun. At the same time, taking the long view is great, but it doesn't make any sense to spend every waking minute in your first few decades working towards having big, big fun in the later decades. Even if you knew for sure that you'd live that long, it's still no way to live.
So, how then can one find that balance? The answer comes down to your values and your goals.
It's your values that the early-death question is supposed to get it--what's so important to you that you'd choose to devote your last hours of life on it? If it doesn't work for me, maybe it's just my own immaturity that puts too high a value on pleasure. But, as long as I stay away from the artificial "last day" question, there are plenty of other things I value--friends, family, the respect of my peers, the satisfaction from doing good work, making a positive difference in the world, helping others. Those things--along with pleasure--are the things that you miss out on if you focus too much on the long term. Keeping them in mind helps you find your balance.
It's your goals that the live-forever question is supposed to get it--what would you do if you felt free to think big? But you don't need that artificial circumstance. However long you might live, you're always free to think big. I have plenty of big projects in mind--books I want to write, fields I want to study, skills I want to master. It's in service of your goals that it's worth deferring short-term pleasures. But these goals only matter if they also advance your values.
For me, it's not about when I might die. It's about where to find the balance between short-term pleasures and long-term goals. It's about thinking big while still living in the moment. It's about living my values every day, not just at the supposed end of my life.
(I'm prepared to concede that I think way too much about this sort of thing.)