Studying is a skill. That might sound obvious, but most high school students are never actually taught how to study—only what to study. So you do what seems reasonable: you reread notes, highlight textbooks, cram the night before, and hope your brain cooperates when the test lands on your desk.
Sometimes it works. Often, it doesn’t.
After years of watching how successful students prepare, and how struggling students unintentionally sabotage themselves, I’ve noticed five study mistakes show up again and again. They’re common, understandable, and fixable.
Think of this article as a conversation between an expert and an apprentice. If you think you’re bad at studying, I can almost guarantee you that you’re actually not. You’ve likely just been practicing the wrong habits.
Let’s fix that.
5 Common Study Mistakes
Many students work hard but still struggle because of common study mistakes they don’t even realize they’re making.
1. Only Focusing on the Questions You’re Getting Right
There’s a special kind of relief that comes from answering a practice question correctly. It feels like proof: I get this. And because that feeling is so satisfying, many students gravitate toward it. They redo problems they already know. They reread chapters they understand. They skim past the questions they missed because they feel uncomfortable.
This is one of the most damaging study habits a student can have.
When you only focus on what you already know, you’re not studying—you’re reassuring yourself. That reassurance feels productive, but it doesn’t build skill. Real learning happens at the exact point where things feel slightly frustrating.
Think of it this way: every wrong answer is a gift. It’s a neon sign pointing directly at the gap in your understanding. If you ignore that sign, you’re choosing comfort over growth.
Strong students do the opposite. They hunt for their mistakes.
After a quiz, test, or practice set, they ask:
- Why did I get this wrong?
- Did I misunderstand the concept, or did I rush?
- Was this a vocabulary issue, a formula issue, or a logic issue?
They don’t just note the correct answer—they write down why their original thinking failed. That reflection is where the learning locks in.
If you want a simple rule to follow, use this one: spend twice as much time reviewing what you got wrong as what you got right. It’s not fun. It is effective.
2. Only Studying the Night Before
Cramming is the academic equivalent of sprinting a marathon. You might survive, but you won’t perform well, and you’ll be exhausted afterward.
Personally, I practiced cramming until the end of my sophomore year of high school. My US history, chemistry, and literature finals each taught me how intense the feeling “burnout” could truly get. And trust me, you don’t ever want to discover how potent burnout can become. It settles inside your brain like a parasite and makes studying feel even tougher than it should be.
In order to avoid feeling that burnout ever again, I had to stop studying the night before.
Here’s the rub, though: studying only the night before a test is tempting because it feels efficient. You’re busy. You have sports, extracurriculars, friends, family, and a life. So you tell yourself you’ll “lock in” the night before.
Perhaps this cram-session will even come with an ego-boost. After all, if you only studied for an hour the night before and you still get an A+ on the test the next day, then you’ll undoubtedly feel like a genius.
The problem is that your brain can’t sustain that habit. You may get an ego boost with a touch of thrill for the first fifteen years of your life; however, research in neurology very clearly reveals that you won’t be able to sustain that pattern for the remaining eighty-five years of your life.
Actually, the scientific literature is quite clear that you won’t be able to continue that pattern even for the next five years. Our brains just don’t work that way on a fundamental, biological level.
Memory isn’t a filing cabinet where you shove information in at the last minute. It’s more like wet cement. It needs time to settle.
When you spread studying out over days or weeks—a technique called spaced repetition—your brain strengthens connections each time you revisit the material. Concepts stop feeling fragile. They become familiar.
Cramming, on the other hand, creates shallow memories. They’re good enough to last until the test ends—and then they vanish.
Here’s what effective students do instead:
- They start with short sessions (20–30 minutes)
- They review a little bit at a time
- They revisit older material while learning new material
This doesn’t require hours a day. It requires consistency.
A powerful shift is replacing the question “How long should I study?” with “How often should I study?” Frequency beats intensity every time.
Remember, a river cuts through a mountain not because of its strength but because of its persistence.
3. Thinking, “I Don’t Need to Write That Down—I’ll Remember It”
This thought has ruined more test scores than almost any other.
In the moment, it feels reasonable. The idea makes sense right now. The teacher explains it clearly. You understand it. Why waste time writing it down?
Because understanding is not the same as remembering.
Your brain is excellent at convincing you that future-you will recall something effortlessly. Future-you, unfortunately, is under pressure, potentially fatigued, and staring at a blank test page.
Writing things down does more than create notes—it forces your brain to process information more deeply. When you write, summarize, paraphrase, or reorganize ideas, you’re actively encoding them into memory.
This is why copying slides word-for-word is less effective than writing notes in your own language. Your brain works harder, and that effort pays off later.
Here’s a helpful mindset: if something feels important enough to test, it’s important enough to write down.
And don’t just write it once. Rewrite it. Turn it into a question. Explain it as if you’re teaching someone else. The goal isn’t pretty notes—it’s durable understanding.
4. Doing Math and Science Calculations in Your Head While Practicing
This mistake shows up constantly in math and science classes, especially among students who are quick thinkers.
Doing calculations in your head feels impressive. It’s fast. It feels efficient. And sometimes, it even works.
But it’s quietly undermining your performance.
Tests aren’t just about getting the right answer—they’re about showing the correct process. When you practice doing steps mentally, you skip the very structure that keeps you from making careless errors under pressure.
Writing out equations does several important things:
- It slows your thinking just enough to catch mistakes
- It makes your logic visible
- It trains you to show work clearly on exams
The same applies to using your calculator when allowed. Practicing without it when you’ll have it on test day doesn’t make you stronger—it makes you inconsistent.
Elite students treat practice like a rehearsal. They solve problems exactly the way they’ll be expected to solve them during the test. Same tools. Same format. Same level of clarity.
If you ever think, “I can just do this in my head,” ask yourself: “Would I want to bet my test score on that?“
5. Not Getting Enough Sleep the Night Before the Test
This might be the most ignored study rule—and the most scientifically supported.
Sleep is not a break from learning. It’s part of learning.
While you sleep, your brain consolidates memories. It decides what information is worth keeping and strengthens those neural connections. Studying late into the night may feel productive, but if it costs you sleep, you’re sabotaging your recall.
A well-rested brain:
- Retrieves information faster
- Thinks more clearly
- Handles stress better
- Makes fewer careless mistakes
An exhausted brain does the opposite.
The smartest thing you can do the night before a test is stop studying earlier than you think you should. Review lightly. Trust the work you’ve already done. Go to bed.
Think of sleep as the final study session, and it’s the one that makes all the others count.
Conclusion: Study Smarter, Not Harder
None of these mistakes mean you’re lazy or incapable. They mean you’re human.
Good studying isn’t about willpower or intelligence. It’s about habits—small, repeatable choices that compound over time. When you focus on your mistakes, space out your studying, write things down, show your work, and protect your sleep, you’re not just preparing for one test.
You’re training your brain to learn.
And that’s a skill you’ll use long after high school ends.
Not sure where to start? A little guidance can help turn these habits into routines. Reach out to schedule a free consult to learn more about our academic tutoring.
