Have you ever skipped a class?If so,Why?用英语回答否的~100字左右

I have had very few times to skip classes; however,some of the classes are both of little avail and as dull as ditch water and,moreover,few of the courses are not wantable of salt when some of the irresponsible teachers instruct their classes in them without any vitality,Therefor,I on several occasions skip them.Of course,I know well that it is awful wrong for us to break the classroom discipline,yet I am always out of patience with such kinds of classes although I try my best to control myself to stick to listening to the teacher.