I'm 59 and I know that I will be leaving behind lots of stuff and someone is going to be a very happy camper!! And imagine what will be there if I make it to 72? In the meantime, I'm going to do the things I want, and there will be finished and unfinished stuff guaranteed, but I'm going to enjoy myself.
That said, I did find myself in your mind frame recently and then I realized I was getting too mired in one thing, man does not live by quilting alone! I love to sew, so I'm working on a guild charity project now, which is due to be turned in by July 1st, and I finished up some burp cloths for one of my students who couldn't finish them because her baby came early, and I did an alterations project for a couple of coworkers and I've always wanted to learn how to paint flowers on rocks so pulling out all the supplies I purchased for that to give it a try - how cool they would look in my rock garden! These are all "short term" type projects, just what I need right now.
So, maybe you'll never get to all those projects you'd like to try, maybe you'll never make up that kit you bought, and maybe you'll never find the perfect pattern for that fabric you can't bring myself to use on just anything, but so what, are you doing something that provides you with enjoyment, contentment and a sense of accomplishment? That's all that really matters.