WHY A PROFESSOR MIGHT BE CRUEL?

OK,today what I will write will not be based on my researches but whether it will be based on what I witnessed in today's Business Finance lecture.Before I went to class,I asked my elders their comments about the Professor of Business and Finance.What I heard was frightening,they said "he is an egoistic,cruel,and ignorant.", these saying created a prejudgment in my mind.I hardly managed to go to class because it was a first day of the classes and I knew there will just be an introduction,moreover the comments about the professor scared me much.Everything was same as I guessed,every student introduced themselves one by one and the turn had come to a cruel,egoistic,and ignorant professor.He started with telling his education life,and the point his he really had a hard university life.Because he was in USA for university he had to work 8 hours per day in order to pay his fees,but it doesn't end with this, he also played a guitar in restaurants and bars 3 hours per day.Is that all?-Nope.He was getting scholarship because he was in football team so it was compulsory for him to join the training almost 3 hours per day again.He also mentioned that they didn't have make-ups in university,if you pass you passed,if you fail you failed;no extra point,no make-up exams.After hearing these experiences of his life,an idea came to my mind because he had these difficulties in his life,because he failed just with a few points,he apply these same method to his students as well.You may think it as a revenge or he is not just aware of what he is doing but because this difficulties still lay somewhere in his mind,in his psychology he applies these methods...So I actually liked him and I will not be annoyed with most of the things he will be doing in the future.It is not just about professors it is about all the human-beings.My point is just try to learn people's past in order to learn why they may act in this way and try to understand them,by this way you will have better relations with any kind of people.Thank you for reading...I am waiting for your comments:)