I love, love, love teaching. I loved the students. I loved learning (from students, new curriculum, etc). I loved it when students excelled or when you saw the "light bulb" moment and everything for them clicked. I remember teaching a sixth grade math class and having a student who was "so proud" that on one particularly tough equation, he got the answer quicker and easier than the teacher

And I was proud of him, too! He was an amazing thinker and a great kid...as they all were!
I hated the admin and the policies in our district. I hated the way students were treated by other teachers, special ed "professionals," principals and staff. (Just a note about how students were treated...only a few staff were "bad," but the ones who were caused lots of issues) I hated the way parents were treated. I hated the entirety of the testing process and "teaching to the test." The curriculum was awful. I hated that my daughter's friend was sexually assaulted on the playground in THIRD GRADE (at a "GOOD" school) and nobody from the school told her parents. I could go on and on...but all of the reasons apart from the ones listed in my opening paragraph are the reasons I decided to NOT teach and to take my own kids out of the school system.
Teaching is hard, no matter what grade or subject you teach. It's hard because of the "hard" kids....the ones that the right teacher can break through to. It's hard because you see so many kids from so many sad situations. It's hard because sometimes keeping control of a classroom is daunting if you're not feeling on top of things that day. It's hard because of the way your heart strings get tugged.