Graduate students are always thinking about the pleasures and travails of grad school, and springtime is a period of especially intense reflection. It’s in the spring, often in March and April, that undergraduates receive their acceptance letters. When that happens, they turn to their teachers, many of them graduate students, for advice. They ask the dreaded, complicated, inevitable question: To go, or not to go?

Answering that question is not easy. For graduate students, being consulted about grad school is a little like starring in one of those “Up” documentaries (“28 Up,” ideally; “35 Up,” in some cases). Your students do the work of Michael Apted, the series’s laconic director, asking all sorts of tough, personal questions. They push you to think about the success and failure of your life projects; to decide whether or not you are happy; to guess what the future holds; to consider your life on a decades-long scale. This particular spring, the whole conversation has been enriched by writers from around the Web, who have weighed in on the pros and cons of graduate school, especially in the humanities. In addition to the usual terrifying articles in the advice section of the Chronicle of Higher Education, a pair of pieces in Slate—“Thesis Hatement,” by Rebecca Schuman, and “Thesis Defense” by Katie Roiphe—have sparked many thoughtful responses from bloggers and journalists. It’s as though a virtual symposium has been convened.

I’m a former humanities graduate student myself—I went to grad school in English from 2003 through 2011 before becoming a journalist, and am still working nights on my dissertation—and I’m impressed by the clarity of the opinions these essays express. (Rebecca Schuman: “Don’t do it. Just don’t”; Katie Roiphe: “It gives you a habit of intellectual isolation that is… useful, bracing, that gives you strength and originality.”) I can’t muster up that clarity myself, though. I’m very glad that I went to graduate school—my life would be different, and definitely worse, without it. But when I’m asked to give students advice about what they should do, I’m stumped. Over time, I’ve come to feel that giving good advice about graduate school is impossible. It’s like giving people advice about whether they should have children, or move to New York, or join the Army, or go to seminary.

Maybe I’ve been in school too long; doctoral study has a way of turning your head into a never-ending seminar, and I’m now capable of having complicated, inconclusive thoughts about nearly any subject. But advice helps people when they are making rational decisions, and the decision to go to grad school in English is essentially irrational. In fact, it’s representative of a whole class of decisions that bring you face to face with the basic unknowability and uncertainty of life.

To begin with, the grad-school decision is hard in all sorts of perfectly ordinary ways. One of them is sample bias. If you’re an undergrad, then most of the grad students you know are hopeful about their careers, and all of the professors you know are successful; it’s a biased sample. Read the harrowing collection of letters from current and former grad students published in the Chronicle, and you encounter the same problem: the letters are written by the kinds of people who read the Chronicle, in response to an article about the horrors of grad school. They, too, are writing out of their personal experiences. It’s pretty much impossible to get an impartial opinion.

Last week, one of my college friends, who now manages vast sums at a hedge fund, visited me. He’s the most rational person I know, so I asked him how he would go about deciding whether to go to grad school in a discipline like English or comparative literature. He dealt immediately with the sample bias problem by turning toward statistics. His first step, he said, would be to ignore the stories of individual grad students, both good and bad. Their experiences are too variable and path-dependent, and their stories are too likely to assume an unwarranted weight in our minds. Instead, he said, he would focus on the “base rates”: that is, on the numbers that give you a broad statistical picture of outcomes from graduate school in the humanities. What percentage of graduate students end up with tenure? (About one in four.) How much more unhappy are graduate students than other people? (About fifty-four per cent of graduate students report feeling so depressed they have “a hard time functioning,” as opposed to ten per cent of the general population.) To make a rational decision, he told me, you have to see the big picture, because your experience is likely to be typical, rather than exceptional. “If you take a broader view of the profession,” he told me, “it seems like a terrible idea to go to graduate school.”

Perhaps that’s the rational conclusion, but, if so, it’s beset on all sides by confounding little puzzles; they act like streams that divert and weaken the river of rational thought. Graduate school, for example, is a one-time-only offer. Very few people start doctoral programs later in life. If you pass it up, you pass it up forever. Given that, isn’t walking away actually the rash decision? (This kind of thinking is a subspecies of the habit of mind psychologists call loss aversion: once you have something, it’s very hard to give it up; if you get into grad school, it’s very hard not to go.) And then there’s the fact that graduate school, no matter how bad an idea it might be in the long term, is almost always fulfilling and worthwhile in the short term. As our conversation continued, my friend was struck by this. “How many people get paid to read what they want to read,” he asked, “and study what they want to study?” He paused. ”If I got into a really good program, I would probably go.”

Thinking about grad school this way is confusing, but it’s confusing in a mundane, dependable way; you’re still thinking about pros and cons, about arguments for and against a course of action. Continue to think about grad school, though, and you’ll enter the realm of the simply unknowable. The conflicting reports you’ll hear from different graduate students speak to the difficulty, perhaps even the impossibility, of judging lengthy experiences. What does it mean to say that a decade of your life is good or bad? That it was worthwhile, or a waste of time? Barring some Proustian effort of recollection, a long period of years, with its vast range of experiences and incidents, simply can’t be judged all at once. The best we can do is use what psychologists call “heuristics”: mental shortcuts that help us draw conclusions quickly.

One of the more well-understood heuristics is called the “peak-end rule.” We tend to judge long experiences (vacations, say) by averaging, more or less, the most intense moment and the end. So a grad student’s account of grad school might not be truly representative of what went on; it might merely combine the best (or worst) with how it all turned out. The most wonderful students will be averaged with the grind of the dissertation; that glorious summer spent reading Kant will be balanced against the horrors of the job market. Essentially, peak-end is an algorithm; it grades graduate school in the same way a software program grades an essay. Sure, a judgment is produced, but it’s only meaningful in a vague, approximate way. At the same time, it raises an important conceptual question: What makes an experience worthwhile? Is it the quality of the experience as it’s happening, or as it’s remembered? Could the stress and anxiety of grad school fade, leaving only the learning behind? (One hopes that the opposite won’t happen.) Perhaps one might say of graduate school what Aeneas said of his struggles: “A joy it will be one day, perhaps, to remember even this.” Today’s unhappiness might be forgotten later, or judged enriching in other ways.