@Laotionne - You are right about the effects of stress. I worked with a news reporter who was having a really tough time adapting to his new job. His editor and his managing editor were always riding him. He was a competent reporter and an intelligent person, but the more and more the stress began to build, the more mistakes he began to make.
He would forget meetings, forget about articles he was supposed to be working on and he even started forgetting conversations he had had.