Why do we do it?

This is a question that I believe every teacher asks themselves from time to time. Especially when you teach at a school that one might consider "rough around the edges." I teach in such a school. I have taught in such a school for the past 2 1/2 years and moved to one that is pretty much the same. Yesterday, I asked myself this question. Sometimes, when I start getting angry or frustrated with my students, I actually have to tell myself that it does not affect my job if they fail. If they try desperately to make it hard on me, I don't have to actually care whether they pass or fail my class. Is it wrong for me to tell myself that? Part of me says, "yes" and part says, "no." In fact, yesterday, I told a class that was being extremely rowdy and disrespectful that if they didn't want me to care whether they passed or failed that I could turn it off like a switch. I want my students to be successful but what price do I have to pay for them to come to my class ready to learn. It doesn't matter how good of a teacher I am. If they don't want to learn, they're not going to learn. My wife, many times, worries about the things I say to my students. I'm not really good at "beating around the bush." I pretty much say what I think my students need to hear, and, sometimes the truth hurts. I work really hard to prepare my students for the next level and tell them up front what the next level looks like. Some "get it" and some don't. In the end, I can only do so much. I really do want to make a difference in the lives of my students and I know that I may never see if I have actually made an impact. I can only try to continue to do what I think is right. Currently, it's not just the students that make me rethink my career timeline. It's also the support I get from the school district (see previous post). I planned on teaching and coaching high school for the next 10-12 years. That may be shortened to 1-3 years depending on where God wants me to be. I just trust that He opens the doors that I should walk through.
Why do we do it? Because we think we might be making a difference. There's no glory, no big paycheck and rarely do we even get a pat on the back. If that was what I was waiting on, I would have already left.