Last Friday, an impromptu conversation in the mailroom at my University jolted my pulse into my aerobic zone. I might have even gone anaerobic, but I am not sure.

This cardiovascular exercise without movement began when one of my closest colleagues suggested to me that his life as a father with a stay-at-home wife was not really all that different from the life I live. I've replayed this conversation several times in my mind, wondering how we reached this point in our discussion in the first place, and, as you might suspect, wondering how this clever, insightful colleague of mine could really imagine the validity of his observation.

At first I wanted to ask him some pressing questions. What was it like to teach with a sick baby on your hip? What was it like to miss a critical meeting because the elementary school called? What was it like to write your talk AND stock the fridge, do the laundry and prepare a master schedule before you left town? I refrained. I felt sure I misunderstood his point. And maybe I did.

I've thought about this conversation ad infinitum in the 100 hours since it took place. Eventually, no matter how I parcel out my thoughts, I return to the simple question of: why? Why does it matter that he understands there is a difference in our lives?

I'm not sure I have an answer. Somehow, though, I want him to know that there is a difference. If he visits his child's preschool, he will be lauded as an extraordinary dad. If I visit my child's preschool, I am shirking my professional responsibilities. He exercises every day at lunchtime. Lunchtime? That is a compound word I learned in second grade that has almost no meaning in my adult life, unless, of course, I am enjoying lunch with a student. Exercise? If I want to exercise, I have to awaken in time to be back home by 6:30 a.m. The pressing demands on my schedule do not permit a break in the middle of the day. I hear him practice his professional talks in his office two or three days before he attends a conference. He never hears me practice my talks since, by now, I usually finish them a night or two before a conference begins and practice them after midnight or, worse yet, on the plane ride to the meeting.

Still, why does it matter that he understands this difference? I still don't have an answer. We both have roughly the same professional responsibilities and certainly the same standards of evaluation. I just take advantage of the flexible time schedule that comes along with this profession a lot more than men with a stay-at-home wife.

But I do worry about the role model I set for my students. Am I really a role model when I have to race off to take care of an unexpected situation that arises? Am I really a role model when I let it slip that I didn't get much sleep last night? Am I really a role model when I have to put their project in a queue that includes not only professional responsibilities ahead of it but a ballet recital too?

Then again, would a really meaningful role model make it look easy? To this day, I regret the model I created at the University of Virginia when, as the first woman graduate student or faculty member in the department of mathematics to have a baby during the academic year (there was only one woman on the faculty at the time), I delivered my baby on a Sunday and returned to the classroom the following Tuesday. I felt heroic at the time. Now I feel uncomfortable for the women who had complications or other difficult situations who came after me.

It occurs to me now, as I've worked through these thoughts by writing about them, that my colleague may have actually paid me a large compliment by seeing no difference in our lives. Maybe, after all, that is a measure of success?