Every year on my birthday I take a few minutes to read Leo Tolstoy's classic story, "The Death of Ivan Ilych." I know I stole this idea from someone, but I can't remember who anymore.
The story, summed up in the pithiest way possible, is basically the following - a man on his deathbed realizes that he's wasted his life. There's also a bunch of religious imagery, criticisms of high society, and the wise peasantry so often seen in Tolstoy's writing, but the theme remains the same - Ivan Ilych cared about the wrong things while he was alive and did not realize it until just before his death at the age of forty-five. Actually, it all pretty much boils down to a single sentence, the first line of the second section of this 60-page novella: "Ivan Ilych's life had been most simple and most ordinary and therefore most terrible."
Ilych's final suffering is mourned by no one since the relationships he cultivated during his lifetime were primarily for personal gain or because they were the "right" ones to have according to society's judgment. He takes positions because they are the kinds of positions that people like him ought to take. He gets married and has children because there is no reason not to (though he later discovers these to be somewhat of an inconvenience for his professional life). He does all the things he's supposed to do until he develops a small discomfort in his side, goes to the doctor, and begins to die a slow and painful death which (along with the sage advice of his kind servant, Gerasim) forces him to realize his errors just in time for a spiritual awakening on the story's final page.
This is a good book to read on one's birthday. Personally, I like to use it as a barometer for my own life and compare its motifs to the choices I've made. I get something new out of it each time I read it, which is the mark of great literature. Plus it's short and can be read quickly during the spare moments of a busy day.
So I turned thirty years old yesterday. Thirty is an interesting cutoff age. In your teens, you have promise. In your twenties, you have potential. But once you're thirty, whatever promise and potential you might have had needs to become action. Nobody looks at a thirty-year-old and says, "Wow, that guy sure has a lot of potential." (The exception to this rule might be politicians, since age is often associated with experience and knowledge despite there being no definitive correlation between them.) To borrow from physics, by thirty you should begin converting your potential into kinetic energy. That's a pretty awful analogy, but I can't think of a better way to express the sentiment.
I don't mean to suggest that if you aren't successful by thirty then you've failed. Continued improvement and lifelong learning are important aspects of personal growth, which includes always striving to be better at what you do. But there comes a point on the continuum of age where you will be rewarded and recognized - at least in part - for what you have already done and not for what you might someday do. And, right or wrong, I think thirty is right around that point.
Ivan Ilych's relevance comes in the recognition that life is about more that the accumulation of titles, accolades, and material stuff. This is particularly important for me to remember, since I like all of those things. And I suppose each of them is fine in moderation. But to make any or all of them the object of your life's pursuit will leave you the same as Ivan Ilych; most simple and most ordinary.