What goes on inside the tweedy brains of professors while they're standing in front of a classroom? Every day they show up and puke knowledge all over the chalkboard or make you do annoying group work, and then they... what? Do they drink, smoke, eat, watch TV, and fuck like the rest of us? Or, when they're finished teaching, do they just go home, unzip their people-suit, crawl into their coffins, and wait there sleeplessly until it's time to teach you again? I taught composition, creative writing, and literature at the college level for six years and so I—zips up people-suit—am perfectly prepared to answer all of your questions.
Does my professor even care about me and my life and what I'm going through right now and my education or what?!? Yes, but it's complicated. Not every one of your professors is a person who has dedicated their lives to teaching. The university hires different tiers of professors, and, given where they're at in their career, each one will have different contractual parameters that determine how much time they can spend caring about you. All will WANT to answer your every question and solve your every need, but politics and self-preservation prevent them from hanging out with you as much as you might want.
I don't understand, my professor is only five years older than me and is also a student—this is a real professor? Good question. And, no—that is a graduate student. They're new to their fields and new to teaching. In return for a tuition waver and a stipend, they teach one or more intro-level courses per quarter, while also taking two or three graduate-level courses themselves. This means at any given moment, they could be grading your paper while reading an article about different approaches to grading papers, while also writing a 25-page seminar paper of their own. Because they're technically "part-time" faculty, these teachers aren't supposed to spend more than 20 hours per week on lesson planning, in-class teaching, holding office hours, and grading. However, they almost always do, partly because they want to do a good job, partly because it just takes that long to adequately prepare for one or two classes, and partly because they want you to succeed. Be gentle with them.
Wait, does that mean I know more than some of my professors? No. You just don't. Stop. Even if you do, you don't. There's a particularly ugly version of this sense of entitlement, and women and international teachers often bear the brunt of it. Your inability to understand someone because of their accent or respect someone for who they are is your problem, not theirs. If you're really not jibing with a teacher, then recognize the problem early and withdraw.
My professor seems harried and underpaid and keeps using the word "adjunct." What is that? Adjunct professors work on a contract basis. If there aren't enough students enrolled in their class, then they lose the class. They're paid only for the classes they teach, and many don't receive benefits until after they've taught at the school for a year. Adjuncts often teach three to five courses per quarter, each of which pays (on the very high end) about $3K each, which if you're any good at math, you know is not enough to live on. Many of them work at more than one university. If they get three classes per quarter for three quarters (an average number), they'll make $27K for the year. Universities are hiring more and more adjuncts to teach their classes because adjuncts are cheap, disposable, and desperate. Treat these people with the most kindness. Of all the teachers you'll encounter, they're teaching the greatest number of students and getting the least amount of pay, and they're often just as good as any tenured professor.
My professor seems really busy and says she's "tenure-track." What does that mean? It means that on top of a heavy course load, she has to perform all kinds of administrative stuff for the department, plus take on other university-related responsibilities so that she can look good when she applies for tenure, plus continue to research and publish in her chosen field. As a result of all that, she's FRAZZLED. But she's got the experience to handle your problems quickly and efficiently so long as you're clear and up front about your needs.
My professor has tenure and seems fancy but does not care about me at all. But I'm a good student! What gives? Comfortably tenured professors often have to do a LOT of academic service—teaching is only one of their jobs. They also have to handle admissions, serve on thesis and dissertation committees, write their books and articles, tear it up at conferences, maybe chair the department for a spell, and produce relevant, earth-shattering work that makes the university look good. Students often choose schools based on the prestige of their faculty, and guess whose gotta keep things nice and prestigey?
One thing that's crazy about many universities: Departments aren't rewarded, monetarily, for good teaching. So if YOU do well, if you go on to grad school or get a job or learn something interesting, the department sees no real love from the university. A department's worth to the university is measured on all that non-teaching stuff—the articles your professors write, the books they publish, and the prestige they bring to the school in other ways. This way of assessing a department's worth is a result of a lot of political stuff that I don't have space to go into here, but, just know: The system is rigged against you.
Will I get a better grade if my professor knows who I am? Oh hell yes. Are you kidding? If you go to every single class, write e-mails like a professional (hot tip: Never start an e-mail with "Soooooooooooo..."), participate without complaint in class activities, and—this is a big one—never once look at your phone, then your professor will take that into consideration when it's time to turn in grades. I've seen a B+ become an A-. I've seen a D transform into a C-.
Caveat: If your professor knows who you are because you're a terrible person who blurts out irrelevant or inflammatory stuff in class, then your professor will give you the exact grade you earned.
Can I have sex with my professor? Assuming you and your professor are both consenting adults, you can totally have sex with each other AFTER YOUR QUARTER WITH THEM IS OVER. Reread that part in all-caps again. It's important. But be sure to thoroughly check out your school's sexual-harassment policy before you make (or take) a move.
You have a body, and the professor has a body, and those bodies aren't automatically desexualized the moment you walk into a classroom. If you're flashing your brights at the front of the class every day, and you see your prof returning the flash, chances are you're probably attracted to each other. If you really want to do something about it, or if they really want to do something about it, even after you find out how much they know about carbon regeneration systems, and even after they find out how little you know about carbon regeneration systems, then do yourself a favor and chill out for 10 weeks. It's only 10 weeks! True love waits. 
