Back to success. It does matter. Metaphysically, your life depends on it. What your life doesn't depend on is whether you're successful in everything.
A wide receiver in the NFL doesn't need to win every game. He does need to catch the football. He doesn't need to catch the football every time it's thrown to him. He does need to stay in shape and repeatedly attempt to catch the football. He doesn't need to be in perfect shape in the off-season or attempt to catch the football if some schmuck throws it at him while he's at the movies with his wife. The point is, we need to be careful not to switch contexts as we talk about "success". A wide receiver in the NFL is a success if he catches the ball a hell of a lot more times than he drops it. He is neither a failure if he drops the ball once nor if his team loses every game in a season. "Success" is essential to be a wide receiver in the NFL. But it's essential in a particular context.
Now let's be crazy and think outside the football field. "Success" is essential on a metaphysical level because if you fail at, say, getting food and shelter, you'll be a corpse. This is why you don't put all your eggs in one basket and stake your life on one particular achievement. You have to diversify your goals. On the other hand, you don't want to be a contrarian asshole and rebel against the utility of baskets. And you only have two hands, for fuck's sake.
So, for the broader goals, you might just aim for one or two. (Like careers or wives.) For smaller or component goals, you might have a bunch of them running concurrently. (Like ten resumes in the mail or registrations to several dating services.) Failure at a component goal isn't so bad, because you've diversified your eggs. (There ought to be a word, not for mixing metaphors with each other, but with the explicit idea they're supposed to be illustrating.)
Of course, some goals are more important than others. And some goals are broader than others, so when you fuck one of these up, you really fuck yourself. But if you think of the big goals as products of component goals, you'll realize that it's kind of hard simply to "fail" at a big goal. If you fail at a big goal, it's most likely because you've failed at one or more of the component goals. If, for example, one of your big goals were to be an airplane designer, but you haven't yet learned how to read or write, it's probably unfair to consider yourself a failure at airplane design. Wait until you can say stuff like "nuts", "bolts", and "propellers" before you give up on that dream.
If you find that you're failing at a lot of the component goals, it's probably time to change the big one. Or at least figure out what the deal is with all the fuck-ups. You don't just suddenly achieve, or suddenly fail, something great. You tend to know whether or not you're getting any closer to it.
Before closing, I should probably address one last question from the naysaying skeptics before they ask it. That is: "What about forces outside your control that can stop you from accomplishing your goals?"
Well, since an answer to that question occurs to me that's already been said as good as it can be said, I might as well finish by quoting it.
"When you reach for the stars, you may not quite get one, but you won't come up with a handful of mud either."
- Leo Burnett (founder of the Leo Burnett Worldwide advertising agency)
It's a convenient coincidence to find good philosophy for living a successful life coming from one of the most brazenly capitalist of all professions. Some of those guys do know what they're doing.