This question calls for a highly complex answer. There are all sorts of lawyers, but they tend to all hate injustice. I am not attracted to the prosecuting side of criminal cases. I like civil law, and defense for criminal law (when they are not scum, which they often aren't).
The government is kinda of crazy, in the U.S. and anywhere else really. America's better than everywhere else, but lots of racism is still built into the system in the U.S., and corruption is common. I think a good lawyer is dedicated to hammering down the bad, and calculating what the bad truly is. Lawyers tend to say "I like helping people" a lot more than "I love ridin on my enemies like tupac", even though I think law students and lawyers alike think about the law in terms of "ridin" just as much as helping.
But all humans have a need for justice. Maslow's hierarchy of needs should have Justice somewhere in the middle. People love seeing wrongdoers get their karma, and people love being compensated for bad *&^% done to them... It is a true need... not a want... but a need. I think the main difference between a layperson and a lawyer would then be, if you like going out and making that happen, and intellectually philosophizing about what is practical and right, and impractical and wrong.