Don’t pretend your clients, in a stressed-out situation, and perhaps the fight of their lives, will act calmly. Serve them as they actually are.

As a frustrated college freshman right after finals, facing the prospect that I would not actually become an astrophysicist (so turned off I was by some of my professors), I burned my “Physics: General Principles” book in the student lounge. My floormates hardly noticed, but they did laugh when, hanging out the window on the 9th floor over Broadway, I saw our physics professor and (this is not a proud moment) I yelled obscenities at him, before dropping burned textbook pages out the window.

I responded to this extreme disappointment by taking, and falling in love with, a class in economics with a man who now runs our national soccer effort. And it was amazing: it was a whole new way to view the world, in particular how we choose, and amongst its bedrock principles was that we are “rational decisionmakers” who try to make the best of our situations. I took class after class based on this view.

And I believed that for a while — before I became an assistant district attorney. Early on in my prosecutorial career I had a case that went to trial in which a woman simply would not leave her ex-girlfriend alone. The trial was a parade of witnesses describing one obsessed act after another about the defendant — who never, ever was going to get her girlfriend back.

I fortunately won at trial. As the judge sentenced the defendant, berating her for harassing someone for so long, I knew the assumption that we act rationally simply did not apply in a lot of cases.

Now, as a business litigator, I realize it applies in almost no cases. When we get stressed, feel wronged, feel threatened, are about to lose it all, believe someone is trying to hurt us — we are not rational decision makers subject to constraints. We are very emotional and irrational human beings.

There is nothing wrong with this. Goodness — would there be any decent Shakespeare plays, Coppola movies, or Flannery O’Connor novels if we were all boringly rational? This is how it is.

The problem is that lawyers often start with this we-are-rational assumption. And it interferes with our work. If we practice based on an understanding of the world that makes sense in books, but not in the world itself, we are not going to serve our clients, and we sure as hell aren’t going to be able to win for them.

I identify here a subset of a bigger problem — practice is not what is taught in schools — but it is a big problem that interferes with our practice. While we should do our best to be dispassionate, unemotional advisors and advocates, we cannot for a moment pretend our clients are going to be the same. We need to accept our clients not simply as who they are in general, but who they are and how they are acting in the matter where we are representing them. And if we are representing them as litigators or trial lawyers it may be one of the most intense experiences of their lives. It is too much to ask that they behave the way economists say they will.

Being smart does not mean being only book smart, but, as is our obligation as lawyers, being real-world smart. We must accept our clients as who they are and where they are. Then we can counsel them and serve them and help them win.

John Balestriere is an entrepreneurial trial lawyer who founded his firm after working as a prosecutor and litigator at a small firm. He is a partner at trial and investigations law firm Balestriere Fariello in New York, where he and his colleagues represent domestic and international clients in litigation, arbitration, appeals, and investigations. You can reach him by email at john.g.balestriere@balestrierefariello.com.