I think that the word of "烦" created by 书生 of the past. Why I say so? If we split out the word of "烦", they are the words of "火" and "页", means 焚书之意. Who will frustrate on the books? Of course those who are reading. 书生 are so "烦" on reading till wish to burn them. That is what I am feeling. Of course, if we stand on another viewpoint, we can also guess that something has troubled 书生 till they are so "烦". The level of their "烦" is accelerated up to the level of burning their favorite = books.
Wahahaha...
*Just for fun*
