If the boss wants to monitor me working they should better not tell me. My entire intelligence melts down in anxiety and performance drops to near-zero if I kno

If the boss wants to monitor me working they should better not tell me. My entire intelligence melts down in anxiety and performance drops to near-zero if I know I am being watched. Why the heck do they want to watch people? What are they trying to discover? Isn't monitoring the results of the job enough?