People don’t understand the job and usually go towards the “I know because I am related or close to someone who is a teacher.” They don’t understand the things, emotionally and physically, you take home with you.
They also don’t understand how much planning goes into it. It’s not like the school year starts and everything magically is there. Do not say “oh well once you have a few years under your belt, you can use the same stuff over”. Every class is different. Different students have different needs. The majority of teachers work their asses off trying to help students with exceptional needs; it is a very hard task to do. Especially when funding is cut and you lose resources such as educational assistants.