Changes have occurred since I entered Harvard 61 years ago. Most obviously, in 1948 the class consisted only of men. Women, in smaller numbers, were shunted off to Radcliffe. The amalgamation of genders and increased diversity of the student body in general are likely to have effects on the university that will not be fully appreciated for at least 50 years.

The treatment of and expectations from athletes may also have changed. Last year’s Louisiana State University starting quarterback, Andrew Hatch, will be returning to Harvard. I remember sitting in the newly opened Lamont Library and noticing with surprise someone from my hometown whom I had not previously considered likely to be admitted. He was approached by an assistant football coach and asked why he was not coming to practice. He stated simply that he was too busy doing schoolwork.

What about the perception that Harvard is the premier academic institution? When the dean of admissions interviewed me, he said, “We mustn’t think of ourselves as the best,” adding with a chuckle sote voce, “but of course we are.” My preference is to think of the school as a metaphor for excellence. Some things at Harvard are not the best. I remember developing a seemingly brilliant chemistry equation and discussing it with a graduate teaching fellow. He liked it. Later, I found that there were two things wrong: The equation was incomplete, and the correct formula had been discovered a century previously.

Time disparity is also reflected in an observation made by a classmate at our 50th reunion. At the time we started, the Spanish-American War was as remote as World War II is to the current class. The Spanish-American War seems impossibly distant. One has to conclude that WWII seems that way to your class. Consider life as a one-way street. Although one’s choices of concentration, vocation, and life partner are not necessarily irrevocable, they are not limitless. Give these choices some rational thought. A degree from Harvard won’t protect you from life. Some doors may open, but others will be at least partially shut.

Here is a brief history of the Class of 2013: At your 25th but not at your 35th reunion, activities will include provision for small children. By your 50th you will still vividly remember your college days. The intervening years will be a blur. You will also be surprised that members attending their 60th will on the whole be in better shape than your class (survivor selection). After 75 years the books on the class will be archived. But look on the bright side. The time from the year I was born until the year your class records are finished will encompass 36 percent of Harvard’s history. Viewed in that perspective, the school is still young.

Answer exam questions as broadly as possible. One student took a social relations exam without enrolling in or auditing the course. His expansive answers drew the comment, “You almost hit the jackpot!” The course professor, who happened to be one of my favorite teachers, tried to get the student expelled. President Conant was more forgiving. Drew G. Faust would likely do likewise, but don’t tempt her.

Presumably, you will consider taking one semester abroad and, given your multiplicity of interests, will get involved in something—sports, acting, politics, writing for The Crimson. I liked sculling on the Charles. Avoid extensive bridge playing. Most of the devoted players in my class dropped out. However, one that didn’t sent five of his children to Harvard, so go figure.

Expect that the best teachers won’t get tenure. In my class, a large number of the students taking math courses appreciated the apparently effortless way one teacher was able to teach a course and a half in one semester. The tenured faculty was not impressed. As explained at our 35th reunion, tenure is a commitment that could last 30 to 40 years. The gifted teacher may burn out. Scholarly productivity is more likely to endure. My experience as a faculty member at a non-Harvard medical school gives credence to the concept. However, I still think that “Dr. R.” could have done both.

One of my classmates is an Olympic gold medalist. Another won a Nobel Prize. One donated enough money to the university that a building was named after him. One caused a change in the course of U.S. history. Only the first of these events was predictable during college. On the other hand, my guess is that 10 percent of my classmates are in poor financial straits. When one such tried to speak up at a reunion, he was ignored.

Be careful how you are quoted in The Crimson. I Googled myself and found that remarks made 60 years ago were still retrievable.

You have four years. To paraphrase Dylan Thomas, after the first four college years, there are no others. Carpe diem.

Stephen J. Seligman ’52 is a research professor at New York Medical College.