I can see the value in both sides of your arguments, Crimzy and Mimzy.
I can see where crimzy doesn't feel "educated" enough to truly decide if he's successful or not, because he still has to live 28 more years before he can really say for sure if he's been successful. I actually agree that I can't decide for myself if I'm ever going to be truly successful.
BUT, I think the word you're looking for crimzy is satisfaction. Not a negative term at all. When you're 60 and all of you're kids are grown and married, you'll find much satisfaction in knowing they're taken care of. You'll likely have a nice nest-egg saved up so there's some more satisfaction. And because you're 32 and not 60, it is understandable for you to be "unsatisfied" with the status-quo - again, not a negative thought at all. That is why you are so driven, because you want to be better and better every day, out-doing yourself.
I am exactly the same way. I feel I can always be achieving more, and am never "satisfied" or "comfortable" with the status-quo. Where can I do better? Where can I go above and beyond my job to really make a difference? Those are questions I ask myself almost daily. It's a passion for living that keeps you hungry for more... more knowledge, more of a grasp on life, more leadership, more promotion... a real "go-getter" as my grandfather would say. Again, very honorable.
But Merriam-Webster defines success as an acheivement, and I can see where crimzy is coming from where the REAL achievement isn't going to happen until you're retired.
But again, success is an acheivement. And we acheive things every day. Success and failure is built into the fabric of time, since the beginning of time (please, no theological debate).
I see success not as a singular determination, but instead as thousands of determinations over the course of one's life. For me, sometimes I'm a success, sometimes I fail. But I'm always learning and growing... especially when I fail.