Teachers, like anyone else, know that hindsight is 20/20.

Business Insider asked teachers for the one thing they wish they knew before becoming a teacher, and more than 50 replied.

Some of the most interesting responses are included below.

There are quite a few steps you need to take before you become a teacher.

To become an elementary school teacher in a public school, for example, you not only need to hold a bachelor's degree, but you also need to prove you have the skills necessary to teach elementary education and have a certain number of hours of supervised educational experience under your belt.

All this job training can only take you so far, however, and inevitably you enter the teaching world not entirely prepared for what's ahead.

To help prevent aspiring teachers from getting caught by surprise, we asked teachers everywhere for one thing they wish they knew before becoming a teacher, and more than 50 teachers responded.

We've anonymously included some of their answers here:

Politics play a huge role

"I wish I knew how political education was. I don't think I was prepared for that."

It's a lot of work

"There is a ton of paperwork, and the job is 24/7. During the school year it is very hard to find a balance between being super teacher and finding time to be one's own person."

The job is so rewarding

"I never expected to love teaching as much as I do."

Your days rarely end when the bell rings

"The paperwork never stops, and it's not just grading, which would be fine — it's the district and state mandated paperwork on top of everything else."

Being an extrovert only carries you so far

"The amount of time you spend in front of a group is exhausting. Having a bad day is magnified in direct relation to how long you have to 'be on' and pretend you are not having a bad day. School isn't just about making a fool out of yourself in front of students. A school is an incredibly social environment where you will also have thousands of opportunities to put your foot in your mouth in front of colleagues, administrators, counselors, and maintenance staff."

It's really not about teaching what you love

"It's about managing the classroom beyond everything else."

You're held responsible for things that are completely out of your control

"I had students who were absent about 50% of the time. I had high school students come in and steal my stuff, push me into walls, refuse to do any work, curse at me and say sexual things to me, and run around the classroom screaming, and I got zero — ZERO — support from the administration. And when these kids inevitably were failing, I was told it was my fault, because my lessons weren't engaging enough."

Parent involvement is key

"Build up relationships with adults as much as you do the children."

You can be stretched thin

"I wish I knew that teaching was such an exploitative career. Not only are you responsible for the behavior and performance of almost a hundred other humans, but it's assumed you're available to teach up to five distinct preps per semester, often without any resources provided by the school. The amount of work involved in such an endeavor is immense and results in a lot of stress and hardly any time for the self.

"For example, if this year I teach US history and world history, next year I might be asked to teach geography, economics, and psychology, even if I have little background in these subjects. While a challenge is wonderful, there is a point when a challenge just weighs you down so much that you're like a walking dead person.

"Basically, as a certified social studies secondary-school teacher, I can be required to teach any of the subjects within the broad category of "social studies" any semester. This is like a programmer being asked to program in a different language every year. Sure, it's fun, but it's also a huge investment of time and energy."

There's no job security

"I could be replaced by any other certified teacher. My years of experience, performance, and relationships in the school community are irrelevant. The system is more concerned with how much work can be gotten out of me, not whether the load is sustainable or negatively affecting my teaching and life. If I complain, I'll be replaced. I could seek work at another school of course, but the schools that have the most jobs available are those with the most discipline issues."

You need to be flexible on a daily basis

"Lesson plans can change the hour before class starts, or you only might be able to get through half of a lesson because something unexpected happened in class, or you realize too late that the kids really aren't ready to move on to the next activity. It's easy to get frustrated with that, but part of what I find is helpful to be an effective teacher is to just take a deep breath and realize that the days never really go as you carefully planned."

Don't expect any breaks

"When you need a minute or two to leave the classroom — maybe you don't feel well, the class is full-moon crazy, or you have to use the bathroom — you are not getting it."

Teaching isn't just about teaching

"We spend more time doing things unrelated to helping the children just so we can keep our job."

You can worry a lot about your students

"I was not prepared to hear about the living situations my students were living in, who had custody of them, or what they had witnessed at such a young age."

There is no separation of work and home

"You're always thinking about 'your babies.'"

Your boss matters

"Your happiness and success as a teacher depends to a certain extent on your principal."

You get emotionally invested in your students

"You will never NOT care about the kids."

It can be exhausting and very stressful

"You probably won't have much of a social life, and you'll end up spending a great deal of money on other people's children."

Responses have been edited for clarity.