Something that all lawyers have learned by the end of law school that most non-lawyers (called "laymen") never learn is that law isn't math. Law usually isn't a clear "If A, then B" scenario.
Consider this example:
A person asks: "If I drink and drive, will I go to jail?"
The layman expects a "yes" or "no" answer. The lawyer answers like this:
"If you drink and drive, that doesn't mean you are driving drunk, so you may not be committing a crime. Even if you are DUI, that doesn't mean you will get caught being DUI. Even if you get caught, that doesn't mean the officer will arrest you. Even if the officer arrests you, that doesn't mean he can prove you guilty. Even if you plea guilty, that doesn't mean you will go to jail. So if you drink and drive you CAN go to jail, but maybe no."
So what the layman sees as a straight line between question and answer, the lawyer sees a multitude of other questions and answers in between. When a layman asks, "Will a jury find me guilty next year of this crime I just got arrested for?" the lawyer has no idea how to answer. The person might as well have asked "Who will win the Superbowl in 2032, and by how much?"
Another example I love is the Goat and the Garden:
A layman awakes one day to find his garden has been eaten. He knows that his neighbor has a goat, and suspects that the goat ate the garden. He confronts his neighbor, a lawyer, and accuses the lawyer's goat of eating the garden. The lawyer replies:
You don't have a garden.
Maybe you have a garden, but I don't have a goat.
Maybe you have a garden, I have a goat, but your garden wasn't eaten.
Maybe you have a garden, I have a goat, your garden was eaten, but my goat has an alibi.
Maybe you have a garden, I have a goat, your garden was eaten, and my goat was there, but another goat ate it.
Maybe you have a garden, I have a goat, my goat ate your garden, but you can't prove it.
Maybe my goat ate your garden, but only because he is legally insane.
Maybe my goat ate your garden in self-defense.
The lesson of this story? Lawyers think step-by-step. Laymen think only beginning and end.