You are told in staff meetings that there is zero tolerance of phones and if you see one, you must demand that it is handed over, then take it immediately to the office and wait while they file it away under pupil's name. (You don't know the child, so have to rely on them telling you truthfully. )
It's morning break. You are on your way to set up your classroom on the other side of the site. You know you will have to move desks and collect litter before the pupils arrive. You want to put out settling activities to get them in quietly.
You see a child in a corridor using their phone. The child won't just hand it over. So you have to negotiate / persuade / follow them around to try and get it. Other children will be laughing, egging them on, swearing at you and FILMING IT ON THEIR PHONES.
You know other members of staff turn a blind eye, so kids will be shocked at having someone enforce the rules.
If the child refuses, you stand there being jeered by a group of teens. If you get the phone, you have to take it to the office, carrying all your books, laptop etc. The office will be busy.
You arrive late and stressed to a scruffy classroom with a queue of rowdy teens at the door. Everyone else's classes have gone in.
The other teachers are based in the department, so they have their own, tidy classrooms, cupboards of resources and they've not had to go out for break. They have already done the register, because their laptops stay turned on in their room. Yours loads slowly, because it's registering on the network.
You have to remember your seating plan and be prepared to argue it out.
You have to find pencils for all the kids that don't have anything to write with.
You are trying to find a marker to write a Learning Objective on the whiteboard. The kids have emptied the drawers.You have to clean the board first.
Pupils are wandering in late, stinking of smoke. The class cheers when they come in...
One time I challenged a girl using her phone openly at break and was sworn at that she was allowed to have it. Turns out the (one of many) temporary Head had informed the pupils in assembly that morning that phones were now ok.
Head just forgot TO TELL THE STAFF!