No matter where you are in life — just starting middle school or long since finished with school — we all have that one teacher. You know the teacher: It’s the teacher who is so tough you do your homework two different ways and triple check with the Internet and your friends and parents and everyone you can think of, just to avoid the wrath of turning in something less-than-perfect. It’s the teacher you and all your friends complain about in private, where his/her eyes can’t smite you where you stand. It’s the teacher who gives you not just one, but two major assignments over break and makes you wish you were homeschooled.

Yeah, THAT teacher.

I am currently dealing with this type of teacher. It’s hard enough being in an AP English class without a teacher who seems to want you to fail. The hardest part for me is that I love to write (I even plan on going to school for Creative Writing in the fall), but every time I turn in an essay, the page is so covered in ink marks that I can hardly decipher all the things I’m being told are wrong with it.

But even though my English teacher sometimes pushes me to my most extreme limits, when I look at the big picture of being in his class, I have to admit that he’s actually taught me some of the most important lessons I’ve ever learned. Here are the lessons I’m learning from the teacher everyone (including me, sometimes) can’t stand:

1. Don’t slack off just because something come naturally to you.

Okay, this is technically a lesson I learned from my older brother, but since he learned it from this exact same teacher when he was in high school, it still counts. My brother was always told that he was a great writer, so when he got to his senior year, he thought he was going to breeze through AP English. When he turned in his first essay, this teacher threw it away and told him not to write so much trash. Was my brother a bad writer? No, he’s never been a bad writer. But until AP English, every essay he wrote was filled with extra fluff that took away from the work as a whole — and no one had called him out on it until that moment. While the execution was harsh, the lesson was fair, and necessary. He learned how to be a better writer, which helped him in college. Tough teachers seem to sense when people are coasting on natural talent instead of striving to be better, and they aren’t afraid to call them out on it.

2. Always look over your work, even if it seems fine.

To be honest, I’m still learning this one, but I know that it’s true and that I need to keep working on it.. We all rush through work sometimes to get to other things, but it’s important to slow down and do it right. I can’t even list how many mistakes my teacher finds in my first drafts. With my creative writing, which I’m super passionate about, I pay close attention to every word I write. But when it came to academic essays and reports, I never really paid much attention to what I was writing, so I would miss obvious mistakes I never would’ve made if it was personal project. Nowadays, I look over my drafts at least twice before I hit print, even if I’m not in love with the topic.

3. Rely on what you know, not what anyone else knows.

For years, I would look to the smartest kid in class for a final answer to any questions my teachers asked. It’s not that I’m not smart; I just never felt confident answering questions. In my ultra-tough AP English class, even the smartest kid in school will stumble at some point. I know that this is just a preview of what it will be like when I’m in college and everyone is bringing their A game. Since everyone is going to be wrong sometimes, it’s up to you to think on your own and find an answer yourself. Yes, it could be wrong, but you’ll be learning to think for yourself, which is valuable even if you miss a question or two along the way.

4. People are going to challenge you for the rest of your life.

Whether you plan on going to college or getting a job right away, there will always be people who will challenge — many even more than your toughest teacher. There will be harsh and downright mean people out there who will make your “evil” teacher look like a sweet angel by comparison. No matter what path you choose, you’ll need a thick skin to deal with all the future crazies, and that’s what you get from a tough teacher.

5. They want us to succeed.

Despite all of the craziness he puts me through, I know that my teacher — like most harsh teachers — actually wants me to succeed. Wait, what? They WANT us to pass? Yes, yes they do. I owe this realization to another teacher, who was listening to me vent about my toughest class. She pointed out that my teacher is twice as hard on himself as he is on us and that he feels like he fails us when we don’t do well on an assignment. It made me look at him differently. That man with the burning coals for eyes actually wants to see us do well and make it through his class. Knowing that motivated me to work even harder.

I’m glad that I have the teacher I have. I may not be able to read his handwriting sometimes, but he’s definitely taught me some lessons that I’ll carry with me long after high school. If you’re reading this, Mr. Wright, I just want to say thank you for pushing me.

Erin Reid is a Maryland writer, Wiccan, and professional sleeper. With her origami dragon on her desk and a cup of tea sitting dangerously close to her open journal, she is currently awaiting her high school graduation so she can start working for her degree in Creative Writing. You can find her on Tumblr.

(Image via Warner Bros.)