When I finished teaching six years ago I was on way more that £22k but for that I had extra responsibilities. I would arrive at 8 and there would be at least two after school meetings a week. You would also have to do a 'playground' duty. You never got to have a lunch break uninterrupted. The marking and preparation was hideous. The pressure to get your students to reach their targets who horrendous - one student half a grade out and you would have to explain yourself. Parents evenings, options evenings, report writing, UCAS references, OFSTED, etc, etc. This is without the stress of having to actually get through a lesson without 'incident'.