"Uhhhhhhhh," said the dean of the engineering school, and it was the worst sound in the world, because it wasn't an indecisive "uh," or a pensive "uhhhh," or even the kind of "uhh" that translates to, "Did no one else notice that a praying mantis just landed in this guy's hair?" It was a space-filling "uhhhhhhhh," a prolonged sound he exuded between real words—between every real word—that made it impossible for me to interrupt and say what I wanted to say. And what I wanted to say was, "I'm dropping out of the engineering school."

It was a conversation this dean had had multiple times, I'm sure—possibly even multiple times that day. When you sign up to become the dean of the engineering school, they probably tell you, "Congratulations! Here's your parking spot! Prepare for an endless stream of undergrads begging for withdrawal slips because multivariable calculus kicked their asses!"

So why did I choose engineering in the first place? Why, at age 18, did I say, "I should commit to this thing I'm not familiar with, that everyone says is really hard"? Heck, until applying for college I assumed an "engineer" was the guy who drives a train wearing a stripy hat. Then, all of a sudden, engineering was not only a possible major, it was half of most colleges: You could either study arts and sciences or you could study engineering.

I knew I liked science, and someone told me that engineering was like science but with problem solving, and I thought, "Well, that's what should really be done to problems. Solve them." So, what the heck, I signed up to major in chemical engineering.

Did you know that chemical engineers design factories that manufacture chemicals? I didn't.

"Uhhhhhhhh," the dean of the engineering school continued, pitch-perfectly groaning the same note. This wasn't good. This was the time when I was supposed to tell him that I had made a mistake for the past three semesters, that I didn't want to be an engineer, and that I wanted to spend the rest of my life studying—oh, the shame—molecular biology.

Older engineers had cautioned me against this. "The dean doesn't like when students leave engineering," they said, taking a bleary-eyed break from their Thermo problem sets at 3:00 in the morning. "If you tell him you want to stay in the sciences, he'll try to convince you that engineering is the same but better."

Two of my friends had tried to drop out of chemical engineering the previous week, both hoping to major in plain old chemistry. The first one left the dean's office (a) crying and (b) still a chemical engineer. The second lied and told the dean she wanted to major in romance languages. The dean was speechless.

So I knew that I had to build a case against chemical engineering. (I like living organisms! I got a 20% on my Intro to Chem E midterm! The juniors and seniors look sad! Heat transfer pisses me off!) But inside the dean's office, instead of arguing, I sat and listened to him say, "Uhhhhhhhh there are no jobs in molecular biology. Uhhhhhhhh if you stay in engineering, you'll have a better skill set. Uhhhhhhhh scientists are afraid of math so they're not doing real work. Uhhhhhhhh … ."

I still don't know how I did it (though I’d imagine that 20% helped). He signed my withdrawal slip, and I emerged from the engineering quad into the beautiful winter sunshine, my head filled with dreams of DNA and mitochondria and never, ever again having to do a Fourier transform.

How foolish I had been, I thought, to choose chemical engineering as my major—and therefore my likely life path—without knowing what the heck it was! And then I began my new major and my new life path (molecular biology) and realized—uh-oh—that I didn't really know what that was, either.

* * *

We all know someone who switched careers late in life, a colleague who woke up one day, looked at his investment-banking power suit, and decided to go back and get a master's degree in Aboriginal literature. Or a friend who, with three kids and an impending retirement, learned that her true calling was not in trade publication editing but neurosurgery. Is it possible to pursue a new career once you realize that you chose wrong for yourself at age 18? Sure. Will you do it? Meh, probably not.

Before we even know what the different science disciplines truly involve, we're expected to choose the one we'll pursue for the rest of our lives. Let me put it more bluntly: We decide whether we're going to become chemical engineers, or computer programmers, or phylogeneticists, at a time in our mental development when our primary concern is dry humping.

For those who haven't yet chosen their career path, here's a brief guide to some of the more popular scientific disciplines:


CREDIT: Hal Mayforth
Click the image to enlarge

Physics

Enjoying all of those funny physics demos in Physics 101? (Look, the professor has a pendulum on a spring! In class! Boing! I’m not paying attention to the thing he’s saying about linear momentum, but boing!)

Majoring in physics is exactly like this. Real-life physicists spend their days dropping fishing weights from the ceiling, firing ping pong balls at stuffed monkeys, and static-ing balloons to the wall.

Astronomy

Many people believe astronomers behave exactly as they're portrayed in the film Contact. This is ridiculous and unrealistic. It's more like Men in Black.

Cellular, molecular, and developmental biology, biochemistry, and biophysics (CMDBBB)

Yes, this is the shortest name most schools can devise for their "miscellaneous biology but not animal biology" department; it’s also called "medical school was too hard." As a CMDBBB major, you'll learn techniques ranging from pipetting to serological pipetting. If you've always wanted to answer life's big questions, this is the major for you—provided life's big questions include, "What specific effect does this tiny mutation have on a random signaling pathway in yeast that no one cares about?"

History of science

Nikola Tesla. The rest is just commentary.

Ecology

Unlike most scientists, who talk about work at work and about things like current events and television among their friends, ecologists are required to never, ever stop talking about ecology. "Say, Jim," your friends will say, which is annoying because your name isn’t Jim. "Did you see last night’s episode of The Bachelor?" "No," you’ll say, "because I was too concerned about FRACKING and ESTUARIES and WATER TABLES and BIODIVERSITY.  But please, enlighten me on which eligible woman Juan Pablo chose for his hometown visit, if it’s so vital." Ecologists have lots of friends.

Psychology

Most undergraduate psych majors chose their field after taking one of those Facebook quizzes to determine their Myers-Briggs personality type. ("I'm INTJ! That is so me!") Actual psychologists spend their time doing much more important things, like paying students $8 an hour to press the space bar every time a red plus sign appears on a computer screen.

Geology

Rocks are one of the most dynamic, fascinating … oh, who the hell are we kidding? It's just rocks, folks. Freaking rocks.

Mathematics

All scientists delight in the fact that laypeople can't understand their fields. But mathematicians are a special kind of sadist, constantly grinning over the knowledge that their research doesn't only baffle laypeople; even the other mathematicians down the hall have no idea what's going on. Come work in mathematics, where you’ll enjoy the satisfaction of laboring in a field in which all problems are either unsolved or trivial.

Applied mathematics

It's like regular mathematics but with fewer ponytails.

Entomology or herpetology

The desire to study insects or lizards for the rest of your life is rare and highly specific. If you don’t know by age 6 that you want to become an entomologist or ichthyologist (I mean, geez, it has "ick" right in the name.), you probably don’t want to.  Most people don’t take a class in college and say, "Dung beetles, eh? I think I’ll hitch my wagon to that star for 50 years."

Engineering

I still don't know what this is. But it pays well. Uhhhhhhhh you should stay in the engineering school … uhhhhhhhh problem sets and Matlab … uhhhhhhhh.

* * *

Before going to college, I dreamed about my career options. I thought about my career options. But do you know what I didn't do? I didn't research my career options.

I never visited a real university lab, never talked to a professor, never even knew that scientific journals existed. Sure, I can hide behind the excuse that it was the mid-'90s and the Internet was basically something clunky and unusable called "AOL Channels" (1045 hours free!), but I'm sure there were ways to learn more.

Maybe I was lazier than today’s kids, but—no, that’s ridiculous. No one is lazier than today’s kids. Still, the idea of picking your major and committing to it at that age is absurd. If the question on Family Feud was "name someone mature and responsible," and you buzzed in and shouted "a teenager," even Ray Combs would look at you like you’re an idiot, and he’s dead.

If your kids are headed off to college, make sure you’ve exposed them to lots of science fields—real ones, not just dropping an egg off the balcony or building a baking-soda-and-vinegar volcano. (If you are a kid headed off to college, congratulations on almost reading Science. Visit some labs, call your parents, and try to avoid Chlamydia.)

And if you find you’ve chosen the wrong major, it’s not too late. Find something else you’re passionate about and make the switch.

Just be sure to think of a good excuse for the dean.

Adam Ruben, Ph.D., is a practicing scientist and the author of Surviving Your Stupid, Stupid Decision to Go to Grad School.

10.1126/science.caredit.a1400053