If you have a single hour of not working at 100% you have to either become a compulsive liar or basically incriminate yourself and have to explain to the assembled masses of bean-counters who review the timesheets why you are, regrettably, a human and not a robot.
Just the concept of measuring your worth solely by how much time you spend pressing buttons with literally no recognition for the outcome is some sort of mental torture.
Fuck it I really should quit shouldn't I?