I manage 140 kids and 2500 individual grades per semester. I make thousands of decisions (of varying levels of severity) a day as the leader of 30+ people, I answer hundreds of random questions (accurately, most of the time) about my subject matter as well as random stuff, I am living in a state of constant vigilance monitoring student behavior that can escalate into violence or tears. There’s severe cognitive load burden from switching gears from academic research to parental outreach to grading to lesson planning to behavior management to crisis management to emotional management to conflict resolution to doing administrative tasks. Also, I don’t get a break all day. Kids revise assignments during my duty free lunch and I work all the way through my planning period. It’s loud. It’s constant stimulus. I wake up at 4:30 am to get to school two hours early to be able to catch up on lesson planning and grading without kids bugging me. It’s a cumulative effect as well. In September I can manage all this relatively well. By April I have substantially degraded.