Experienced (20 years) teacher here.
The job in no way looks like it did when I first joined the profession.
I get in at 8. Mark, prep etc until 8,40 when the children come in.
Register. Collective worship - I play the piano so am in all the assemblies where other teachers stay out to listen to readers/finish off their prep/see groups of children.
Then it's lesson - break - lesson - lunch then a full afternoon because there's no break. After school is gate duty. Staff meetings. Year group meeting. Or otherwise trying to stay on top of marking and assessment.
What I find tiring is how full-on you have to be when teaching. You obviously have to know what you are trying to teach, the methods that you are going to use, what you are looking for in terms of assessment (inc ongoing afl strategies) and how best to help the children achieve what you want them to learn. Any and all resources need to have been found/made/ready for the children to use.
At the same time you have 30 children and their different needs to cater for. They work at different speeds so you have to plan for those who will finish and those who won't get finished at all. In my class I have children who are hearing impaired/visually impaired/autistic/adhd. A standard mainstream class.
You have to help some children with what they are doing so they can do their best. If you take your eye off the rest of the class to help a child any one of the handful (it used to be one or two in an average class when I started teaching, not 5 or 6) children will stop working or start chatting/messing. Parents expect their children to be listened to read individually weekly (or more) but when do I find the time? Especially as when I say I've listened to children as part of guided reading that's 'not good enough'. Often the parents who complain don't bloody listen to their own child read, but don't get me started on that one If I sit with a reader I can't help children with their work.
There's a school behaviour system. Which is backed up (unlike in some schools) by the SMT. I have to adjust my behaviour management techniques according to the needs of the children in my class. And remember how far down a particular scale any particluar child who is causing a problem is. Are they on a reminder? A warning? Do they lose golden time? Did they lose golden time last week? Do I involve the HT? Do I need to involve parents? If I involve parents, will I get backup? Or will I get their backs up?
Our topics are changing. Our curriculum (Wales) is due a massive change and we are preparing for it. Our performace management is about to change - online - ad it's just one more new thing to take on board. Topic planning is supposed to take more notice of what children want to learn about, while still meeting the curriculum. So you can't just follow a topic plan and know where you will be 4 weeks in to a topic. 'Recyclig planning' is seen as a bad thing.
I manage my time well. Rarely take anything home with me at 5-6pm and don't do much work at home. But when the new curriculum does come in that will probably change.
I wouldn't dare say it was the most exhausting job though. I've worked ina supermarket and as a waitress and in a clothes shop and found being rushed off my feet for long periods of time to be very tiring. I'd never be a nurse doing 13 hour shifts!