Law school is an adventure. A learning experience. For most, they start it, and flounder around for awhile trying to figure out what the professors are looking for. And all of a sudden, for most of us, it is obvious. And that, to some extent, is when you start thinking like a lawyer.
Indeed, that is one reason that law school is somewhat different than other graduate schools. For example, graduate engineering school is little different from undergraduate engineering school, except that things are taught a little bit more theoretically, a little more abstractly. And engineering school only really differs from physics, math, and chemistry, in that practical applications are stressed over the theoretical. Thus, in a math class, you may learn to differentiate an equation, and after you can do it relatively well, you go on. In engineering school, you do it over and over again until you can do it in your sleep. In other words, it is merely a matter of degree.
But law school is different. It teaches you a different way of thinking. The classic movie on teaching this is "Paper Chase". But there are some surprisingly accurate scenes in "Legally Blonde" (most of it, of course, is pure gobbledygook).
So, how is this way of thinking different? It is a little hard for me to put this in words, especially since, being raised by an attorney, I have always thought this way somewhat. But here goes.
First, you learn to be objective and dispassionate. To a great extent, this means separating yourself from a conflict, or indeed, anything, and trying to look at it without emotion. For one thing, you have to be able to put yourself in your opponent's shoes so as to anticipate what he is going to do and argue.
Second, you have to be analytical. Law schools mostly use a peculiar type of test, called "issue spotting", where you are given a fact pattern, such as: "X and Y entered into a contract to do Z. X did this, and Y did that. What is the outcome?" Obviously a lot more complex than that, often a page or so in length. Much of what is in one of these problems is superfluous. Maybe. One popular way that law students are taught to answer this sort of question is called IRAC: Issue, Rule, Analysis, and Conclusion. You cruise through these fact patterns looking for relevant issues (if you spot irrelevant issues, typically they are either ignored or count against you in grading, depending on the Prof. - but in any case, discussing them waste valuable time). You then cite the proper rule, analyze the facts in view of that rule, and then come to a conclusion. This is repeated for as many issues as you can spot. If you are good, you can also spot the subrules and apply them, ad nauseum.
Third, combined with analysis is reading comprehension. In particular, in law school you read and analyze hundreds of cases. Indeed, when I was in law school, my classes would average 100 pages of court cases a week, each. For one thing, this is where you learn those rules you use in the analysis above. But it is not like engineering, where you are given the equation. Rather, you learn to read cases objectively and try to develop the relevant rules from this. Cases tend to have five elements: facts, rules, analysis, conclusions, and dicta. The conclusions are the meat of the cases, forming the rules for other cases. Orbiter Dicta is stuff that is in there that is really (mostly) irrelevant, though it often appears to be relevant. It may look like a new rule, but if it is not necessary for the ultimate finding in the case, for one party or the other, it is dicta, and thus irrelevant. But in real life, you find that in a surprising amount of the time, some dicta turns out to be precedential, though it isn't supposed to be. But once another court has taken dicta as precedential as part of the rules it uses, then it becomes such for other cases. Luckily, this is a portion of real life law that is not covered heavily in law school, with most of the lines of cases used for teaching being fairly clean.
Note, BTW, that in real life in law school, many, if not most, law school students quickly discover study aids that parallel case books summarizing cases, and other study aids that outline the law, putting it in a form that is much easier to understand. And these follow you into practice, with numerous practice aids doing similar. That said, if you can't do the underlying analysis and critical reading, you will never do well in the practice of law (or, typically in law school).
Next, you learn to think literally. My daughter often tells me to "wait a second". I do, and then tell her that her time is up. She meant wait a minute or two, but that is not what she said. Similarly, she often asks if she can do something. I retort, "I don't know, can you?", meaning is she capable of doing such. Then she corrects herself and asks if she may do it. As this is a learning experience for her, and I am an indulgent dad, I almost always say yes. I often wondered where I got this, until recently I told my father my engine was missing. He asked me if I had found it yet. And opined that engines are usually too big to lose, and are typically bolted down into a car. Obviously, I meant that the engine was running rough, probably missing spark to one cylinder. But that is not what I said.
I know this all sounds silly. And it is great fun for us, in a family of lawyers. But it has a serious side. Precise meanings are important in the practice of law. You see this in contracts. You see this in statutes.
Here is an example. I entered into a lease/purchase agreement for selling my house. The original contract offer had a section where the rent would go into escrow to pay all PITI on the loans outstanding. We countered that it would cover the 1st and 2nd mortgages. The tenant/buyer later claimed that the nondisclosure of a 3rd was misrepresentation, because only the 1st and 2nd were mentioned. It of course wasn't, because all that I had said was that the rent was to cover the 1st and 2nd, not that there weren't more liens.
One corollary here is that this literalness helps in seeing the gray areas. These are most often places where assumptions mask ambiguity that often results from literal interpretation of language.
This brings me to the last item, which is that attorneys are paranoid. Not in the way that a pot smoker gets - that everyone is out to get them, but rather in seeing all those gray areas of ambiguity that most people, esp. non attorneys, miss.
I have always done well in this area, as it parallels to some extent computer programming, which I did for 15 years. There, you try to anticipate what might go wrong. The practice of law is very similar. You try to anticipate what might go wrong, and what the other side might do with certain language, and endeavor to fix it. You always have to figure that the other side is sneaker than you are. Also, that Murphy usually sticks his head in there somehow (i.e., if it can go wrong, it will). The better your imagination here, the better you do.
Probably not surprisingly, after all this, if you are an attorney, it is usually fairly easy to figure out whether or not someone else is an attorney. If someone thinks pretty much the same way you do about many of life's situations, then it is likely that either he is an attorney, or has spent a lot of time around us.