You might find inspiring the essay on The role of a professor , by Prof. Walter Noll (Carnegie Mellon University). I often find myself in both of the following circumstances described by Prof. W. Noll:
"The teacher's focus is on his students. His task is to convey a fixed body of knowledge to his students and to worry about the best way to do so. He normally follows a textbook and a "syllabus". A very important part of his job is to assign homework and to give tests to find out how much his students are learning. He pays attention to what the students think of him and his performance. He sympathizes with his students' worry about their grades.
The professor's focus is on his subject. He "lives" his subject and cannot easily switch it off, even while lying in bed awake or on vacation. He recreates the subject in his mind each time he lectures on it. He cannot know, in the beginning of a course, exactly how and in what order he will present the material. He may even, in the middle of the course, change his mind about what material to include or exclude. He always tries to find a new approach to and better insight into the subject of his course. He almost never gives a course twice in the same way, and he considers it anathema to 2 have to follow a textbook and a syllabus. He is pleased if some students follow and appreciate his efforts, but he finds homework, tests, and grades a nuisance. As the famous British mathematician G.H. Hardy put it in his book A Mathematician's Apology: " I hate 'teaching', and have had to do very little,... ; I love lecturing, and have lectured a great deal to extremely able classes;..." ", by W. Noll.