You may have started the semester not knowing a soul in any of your classes, but by now you probably know more than you’d ever wish to.

When you routinely spend 75 minutes a day with a group of people, you’ll quickly learn about everyone’s quirks and mannerisms.

I know I have.

We’ve all been taught that being prejudiced is wrong, and that we should rise above the urge to let appearance and stereotypes guide our opinion on people.

But when certain prejudices prove to be true time after time, your assumptions aren’t insensitive. You’re just playing the odds.

I’ve made many wagers with myself about my classmates this semester.

And the same can be said for every semester before this one. Only now, it takes me less time, and I can know what to expect from certain people on day one, judging by a handful of superficial qualities.

Example: if I see a man in his 50s sitting in front of me in class and he’s not preparing to give a lecture, I groan. This guy’s going to be trouble.

Older students, as a general rule, operate at a slower pace, causing frustration for the younger students who live with a greater sense of urgency.

Which is ironic, seeing as students in their 20s have all the time in the world, while time is in very limited quantity for some elderly students.

I don’t believe that every older student is a pain, of course, but I’m wise enough in my fifth year of college to be wary when I have a class with one.

(I’m also wise enough to know that I just opened myself up to “If you were wise, you’d have graduated by now” jokes. Spare me. I don’t need you telling me I’m a failure. That’s what parents are for.)

Despite their race against the biological clock, some elder students can’t help but act as anchors in the classroom. They constantly weigh everyone else down, forcing the entire class to move at the speed of old.

I once witnessed an older woman try to set the record for most times saying, “Can you go back to the last slide?” in one class period.

As frustrating as that can be, dealing with that type of student is far from the worst. My least favorite classmate each semester has always been someone of my age.

The worst type is the overzealous attention-seeker. They tend to be male but I’m sure if they put their mind to it, women could play the role just as well.

All this coming from a guy who writes a weekly self-indulgent opinion column that borders on narcissism and is often mediocre at best even though he probably thinks it’s hilarious?

Yes. Even I get sick of one’s need to be noticed at times.

Enthusiasm for a class is one thing, but no one cares about your personal anecdote that only kind of relates to the subject.

Most of us know this and keep our mouths shut. In fact, I think most normal people would prefer going unnoticed in class. We (yes, I’m including myself in the “normal” group) fear our classmates thinking, “Why does this pretentious d-bag keep going on and on?”

The people who don’t have this thought, and enjoy loudly interjecting at every possible moment, are the people whose mothers told them to never care about what anyone else thinks about them.

Yeah, that’s all fine and dandy, Mom. But at some point during your kid’s upbringing a very necessary hug wasn’t given and now he’s doomed to spend the rest of his life trying to make up for it by getting all eyes in every room squarely locked on him.

Writing this column has made me feel a little guilty. I don’t want to come off as mean guy. I just wanted to poke some fun at the class characters who can drive me a little nuts.

But some characters are bad, and not bad in an awesome Hans Gruber or Dennis Hopper in “Speed” kind of way. They’re bad in an unforgivable, I-had-to-stay-in-class-three-extra-minutes-thanks-to-that-inane-question sort of way.

They don’t deserve to be thrown out of a skyscraper or beheaded by a moving train, but the next time I have to watch one of their performances, you can bet I’ll be daydreaming about it.

Dante Frattini can be reached at [email protected].